Before doing these setting go to

Tools -> folder options -> View and under the Hidden Files and Folders

enable ‘Show hidden files and folders‘ and

un check ‘Hide protected operation System files[Recommended]‘

click ok for the popup

1 – Delete the unwanted user settings

Delete everything from

C:\Documents and Settings\[user name]\Application Data
C:\Documents and Settings\[user name]\Local Settings\Temp
C:\Documents and Settings\[user name]\Local Settings\Application Data
C:\Documents and Settings\[user name]\Local Settings\History
C:\Documents and Settings\[user name]\Local Settings\Temporary Internet Files

Don’t have any junk files in Desktop

repeat the above for all the users in the system

2 – Delete unwanted uninstall files[files starting with ‘$’] from

C:\WINDOWS
also
Empty C:\Temp (if it exists) and C:\Windows\Temp

3 – Delete from

C:\WINDOWS\SoftwareDistribution

4 – Delete from

C:\WINDOWS\system32\LogFiles

5 – uninstall unwanted programs from control panel and also from the program files[some files will be still residing inside program files even after the the application is uninstalled]

6 – Search for *.log files in C: and delete everything.. sometimes this will take some GB space

with all the above steps if you feel the performance and the space is not increased then try increasing the virtual memory or don’t have it

If the virtual memory is set then you will find two files in C:\hiberfil.sys and C:\pagefile.sys both will be having the size corresponding to the allocated memory size

to disable virtual memory

Right click ‘My Computer‘ -> got to ‘properties‘

Click the ‘Advanced Tab‘ in the System Properties window

In the Performance section, click the ‘Settings‘ button

Click on the ‘Advanced Tab‘ in Performance options window

In the Virtual Memory Section, click the ‘Change‘ button

Select the ‘No Paging file‘ option and click on ‘Set‘ button

This will ask for a restart of the machine

restart the machine and you will find some space in you C: for sure