Posts Tagged ‘active directory’

How to disable Windows pagefile.sys and hiberfil.sys to temporary or permamently save disk space if space is critically low

Monday, March 28th, 2022


Sometimes you have to work with Windows 7 / 8 / 10 PCs  etc. that has a very small partition C:\
drive or othertimes due to whatever the disk got filled up with time and has only few megabytes left
and this totally broke up the windows performance as Windows OS becomes terribly sluggish and even
simple things as opening Internet Browser (Chrome / Firefox / Opera ) or Windows Explorer stones the PC performance.

You might of course try to use something like Spacesniffer tool (a great tool to find lost data space on PC s short description on it is found in my previous article how to
delete temporary Internet Files and Folders to to speed up and free disk space
 ) or use CCleaner to clean up a bit the pc.
Sometimes this is not enough though or it is not possible to do at all the main
partition disk C:\ is anyhow too much low (only 30-50MB are available on HDD) or the Physical or Virtual Machine containing the OS is filled with important data
and you couldn't risk to remove anything including Internet Temporary files, browsing cookies … whatever.

Lets say you are the fate chosen guy as sysadmin to face this uneasy situation and have no easy
way to add disk space from another present free space partition or could not add a new SATA hard drive
SSD drive, what should you do?

The solution wipe off pagefile.sys and hiberfil.sys

Usually every Windows installation has a pagefile.sys and hiberfil.sys.

  • pagefile.sys – is the default file that is used as a swap file, immediately once the machine runs out of memory. For Unix / Linux users better understanding pagefile.sys is the equivallent of Linux's swap partition. Of course as the pagefile is in a file and not in separate partition the swapping in Windows is perhaps generally worse than in Linux.
  • hiberfil.sys – is used to store data from the machine on machine Hibernation (for those who use the feature)

Pagefile.sys which depending on the configured RAM memory on the OS could takes up up to 5 – 8 GB, there hanging around doing nothing but just occupying space. Thus a temporary workaround that could free you some space even though it will degrade performance and on servers and production machines this is not a good solution on just user machines, where you temporary need to free space any other important task you can free up space
by seriously reducing the preconfigured default size of pagefile.sys (which usually is 1.5 times the active memory on the OS – hence if you have 4GB you would have a 6Gigabytes of pagefile.sys).

Other possibility especially on laptop and movable devices running Win OS is to disable hiberfil.sys, read below how this is done.

The temporary solution here is to simply free space by either reducing the pagefile.sys or completely disabling it

1. Disable pagefile.sys on Windows XP, Windows 7 / 8 / 10 / 11

The GUI interface to disable pagefile across all NT based Windows OS-es is quite similar, the only difference is newer versions of Windows has slightly more options.

1.1 Disable pagefile on Windows XP

Quickest way is to find pagefile.sys settings from GUI menus

1. Computer (My Computer) – right click mouse
2. Properties (System Preperties will appear)
3. Advanced (tab) 
4. Settings
5. Advanced (tab)
6. Change button


1.2 Disable pagefile on Windows 7





Once applied you'll be required to reboot the PC



1.3 Disable Increase / Decrease pagefile.sys on Windows 10 / Win 11




1.4 Make Windows clear pagefile.sys on shutdown

On home PCs it might be useful thing to clear up ( nullify) pagefile.sys on shutdown, that could save you some disk space on every reboot, until file continuously grows to its configured Maximum.



Modify registry key at location


HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management


You can apply the value also via a registry file you can get the Enable Clearpagefile at shutdown here .reg.

2. Manipulating pagefile.sys size and file delete from command line with wmic tool 

For scripting purposes you might want to use the wmic pagefile which can do increase / decrase or delete the file without GUI, that is very helpful if you have to admin a Windows Domain (Active Directory)

[hipo.WINDOWS-PC] ➤ wmic pagefile /?

PAGEFILE – Virtual memory file swapping management.

HINT: BNF for Alias usage.
(<alias> [WMIObject] | [] | [] ) [].


PAGEFILE CREATE <assign list>


[hipo.WINDOWS-PC] ➤ wmic pagefile
AllocatedBaseSize  Caption          CurrentUsage  Description      InstallDate                Name             PeakUsage  Status  TempPageFile
4709               C:\pagefile.sys  499           C:\pagefile.sys  20200912061902.938000+180  C:\pagefile.sys  525                FALSE


[hipo.WINDOWS-PC] ➤ wmic pagefile list /format:list




  • To change the Initial Size or Maximum Size of Pagefile use:

➤ wmic pagefileset where name="C:\\pagefile.sys" set InitialSize=2048,MaximumSize=2048

  • To move the pagefile / change location of pagefile to less occupied disk drive partition (i.e. D:\ drive)



    Sometimes you might have multiple drives on the PC and some of them might be having multitudes of gigabytes while main drive C:\ could be fully occupied due to initial install bad drive organization, in that case a good work arount to save you space so you can work normally with the server is just to temporary or permanently move pagefile to another drive.

wmic pagefileset where name="D:\\pagefile.sys" set InitialSize=2048,MaximumSize=2048

!! CONSIDER !!! 

That if you have the option to move the pagefile.sys for best performance it is advicable to place the file inside another physical disk, preferrably a Solid State Drive one, SATA disks are too slow and reduced Input / Output disk operations will lead to degraded performance, if there is lack of memory (i.e. pagefile.sys is actively open read and wrote in).

  • To delete pagefile.sys 

➤ wmic pagefileset where name="C:\\pagefile.sys" delete


If for some reason you prefer to not use wmic but simple del command you can delete pagefile.sys also by:

Removing file default "Hidden" and "system" file attributes – set for security reasons as the file is a system file usually not touched by user. This will save you from "permission denied" errors:

➤ attrib -s -h %systemdrive%\pagefile.sys

Delete the file:

➤ del /a /q %systemdrive%\pagefile.sys

3. Disable hibernation on Windows 7 / 8 and Win 10 / 11

Disabling hibernation file hiberfil.sys can also free up some space, especially if the hibernation has been actively used before and the file is written with data. Of course, that is more common on notebooks.
Windows hibernation has significantly improved over time though i didn't have very pleasant experience in the past and I prefer to disable it just in case.

3.1 Disable Windows 7 / 8 / 10 / 11 hibernation from GUI 

Disable it through:

Control Panel -> All Control Panel Items -> Power Options -> Edit Plan Settings -> Change advanced power settings

 like shown in below screenshot:



3.2 Disable Windows 7 / 8 / 10 / 11 hibernation from command line

Disable hibernation Is done in the same way through the powercfg.exe command, to disable it
if you're cut of disk space and you want to save space from it:

run as Administrator in Command Line Windows (cmd.exe)

powercfg.exe /hibernate off

If you later need to switch on hibernation

powercfg.exe /hibernate on


3.3 Disable Windows hibernation on legacy Windows XP

On XP to disable hibernation open

1. Power Options Properties
2. Select Hibernate
3. Select Enable Hibernation to clear the checkbox and disable Hibernation mode. 
4. Select OK to apply the change.

Close the Power Options Properties box. 


To sum it up

We have learned some basics on Windows swapping and hibernation and i've tried to give some insight on how thiese files if misconfigured could lead to degraded Win OS performance. In any case using SSD as of 2022 to store both files is a best practice for machines that has plenty of memory always try to completely disable / remove the files. It was shown how  to manage pagefile.sys and hiberfil.sys across Windows Operating Systems different versions both from GUI and via command line as well as how you can configure pagefile.sys to be cleared up on pc reboot.

Change Windows 10 default lock screen image via win registry LockScreenImage key change

Tuesday, September 21st, 2021


If you do work for a corporation on a Windows machine that is part of Windows Active Directory domain or a Microsoft 365 environment and your Domain admimistrator after some of the scheduled updates. Has enforced a Windows lock screen image change.
You  might be surprised to have some annoying corporation logo picture shown as a default Lock Screen image on your computer on next reoboot. Perhaps for some people it doesn't matter but for as a person who seriously like customizations, and a valuer of
freedom having an enforced picture logo each time I press CTRL + L (To lock my computer) is really annoying.

The logical question hence was how to reverse my desired image as  a default lock screen to enkoy. Some would enjoy some relaxing picture of a Woods, Cave or whatever Natural place landscape. I personally prefer simplicity so I simply use a simple purely black

To do it you'll have anyways to have some kind of superuser access to the computer. At the company I'm epmloyeed, it is possible to temporary request Administrator access this is done via a software installed on the machine. So once I request it I become
Administratof of machine for 20 minutes. In that time I do used a 'Run as Administartor' command prompt cmd.exe and inside Windows registry do the following Registry change.

The first logical thing to do is to try to manually set the picture via:

Settings ->  Lock Screen

But unfortunately as you can see in below screenshot, there was no way to change the LockScreen background image.


In Windows Registry Editor

I had to go to registry path


And from there in create a new "String Value" key


so full registry key path should be equal to:


The value to set is:



If you want to set a black background picture for LockScreen like me you can download my black background picture from here.

That's all press CTRL + L  key combination and the black screen background lock screen picture will appear !

Hopefully the Domain admin, would not soon enforce some policty to update the registry keys or return your old registry database from backup if something crashs out with something strange to break just set configuration.

To test whether the setting will stay permanent after the next scheduled Windows PC update of policies enforced by the Active Directory (AD) sysadmin, run manually from CMD.EXE

C:\> gpupdate /force

The command will download latest policies from Windows Domain, try to lock the screen once again with Control + L, if the background picture is still there most likely the Picture change would stay for a long.
If you get again the corporation preset domain background instead,  you're out of luck and will have to follow the same steps every, now and then after a domani policy update.

Enjoy your new smooth LockScreen Image 🙂


Testing your local network for open Windows shares from Linux router

Friday, June 28th, 2013

Windows sharing testing local network for open shared directories Samba Software logo

Whether you administrate local Windows network behind a DMZ router, It is useful to routinely scan from Linux router which Windows hosts on the network has enabled sharing? The reason is some Windows user might share something by mistake which is not supposed to be shared without even he realizes this.

 In case, where new Linux router is configured and Windows hosts behind it can't locate each other on network make sure you have in your firewall before any filtering (REJECT / DROP) firewall rules:

iptables -A INPUT -s -m state --state NEW -p tcp --dport 137 -j ACCEPT
iptables -A INPUT  -s -m state --state NEW -p tcp --dport 138 -j ACCEPT
iptables -A INPUT  -s -m state --state NEW -p tcp --dport 139 -j ACCEPT
iptables -A INPUT  -s -m state --state NEW -p tcp --dport 445 -j ACCEPT

iptables -A INPUT -s -m state --state NEW -p tcp --dport 445 -j REJECT
iptables -A INPUT -s -m state --state NEW -p tcp --dport 138 -j REJECT
iptables -A INPUT -s -m state --state NEW -p tcp --dport 139 -j REJECT
iptables -A INPUT -s -m state --state NEW -p tcp --dport 137 -j REJECT

(Qquickest way to place rules to exec on next boot is via /etc/rc.local)

Once set, to check all is fine with fwall rules:

router:~# iptables -L INPUT -n

Chain INPUT (policy ACCEPT)

target     prot opt source               destination         

ACCEPT     tcp  —           state NEW tcp dpt:137
ACCEPT     tcp  —           state NEW tcp dpt:138
ACCEPT     tcp  —           state NEW tcp dpt:139
ACCEPT     tcp  —           state NEW tcp dpt:445 
REJECT tcp — state NEW tcp dpt:445 reject-with icmp-port-unreachable
REJECT tcp — state NEW tcp dpt:138 reject-with icmp-port-unreachable
REJECT tcp — state NEW tcp dpt:139 reject-with icmp-port-unreachable
REJECT tcp — state NEW tcp dpt:137 reject-with icmp-port-unreachable

On CentOS / Fedora / Redhat router place below rules in /etc/sysconfig/iptablesdefault firewall configuration file for RPM based distros:

-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 137 -j ACCEPT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 138 -j ACCEPT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 139 -j ACCEPT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 445 -j ACCEPT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 137 -j REJECT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 138 -j REJECT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 139 -j REJECT
-A RH-Firewall-1-INPUT -s -m state --state NEW -p tcp --dport 445 -j REJECT

After that check lets say whether Windows Samba shares ports are reachable:

 To check hosts with Sharing easiest way is to scan your network C class range with nmap for all ports through which Windows Samba shares communicate – i.e. check for open state TCP / UDP port numbers 139,137,139,445 list of samba used default ports is in  /etc/services

router:~# grep netbios /etc/services

netbios-ns 137/tcp # NETBIOS Name Service
netbios-ns 137/udp
netbios-dgm 138/tcp # NETBIOS Datagram Service
netbios-dgm 138/udp
netbios-ssn 139/tcp # NETBIOS session service
netbios-ssn 139/udp

Note that Port 445 microsoft-ds is not in /etc/services because it is not common used (only used whether Windows hosts are using Active Directory)

router:~# nmap -p 139,137,139,445

Interesting ports on

137/tcp filtered netbios-ns
139/tcp open     netbios-ssn
445/tcp open     microsoft-ds
MAC Address: 00:AA:4D:2F:4D:A2 (Giga-byte Technology Co.)

Interesting ports on

137/tcp filtered netbios-ns
139/tcp open     netbios-ssn
445/tcp open     microsoft-ds
MAC Address: 3C:B9:2B:76:A6:08 (Unknown)