Do Not remove any System Restore Points if your computer is still infected as an infected computer that can be recovered is better than a computer that cannot restart.
You should not use any type of temporary file cleaners until your system has been cleaned from all infections doing so could potentially make it difficult or impossible to recover important data.
You should Create a New Restore Point to prevent possible reinfection from an old one if you've recently cleaned up from an infection.
Some of the malware you picked up could have been saved in System Restore.
Since this is a protected directory your tools cannot access to delete these files, they sometimes can reinfect your system if you accidentally use an old restore point.
Setting a new restore point AFTER cleaning your system will help prevent this and enable your computer to "roll-back" to a clean working state.
The easiest and safest way to do this is:
- Go to Start > Programs > Accessories > System Tools and click "System Restore".
- If the shortcut is missing you can also click on START > RUN > and type in %SystemRoot%\system32\restore\rstrui.exe and click OK
- Choose the radio button marked "Create a Restore Point" on the first screen then click "Next".
- Give the new Restore Point a name, then click "Create".
- The new point will be stamped with the current date and time. Keep a log of this so you can find it easily should you need to use System Restore.
- Then use the Disk Cleanup to remove all but the most recently created Restore Point.
- Go to Start > Run and type: Cleanmgr.exe
- Select the drive where Windows is installed and click "Ok". Disk Cleanup will scan your files for several minutes, then open.
- Click the "More Options" tab, then click the "Clean up" button under System Restore.
- Click Ok. You will be prompted with "Are you sure you want to delete all but the most recent restore point?"
- Click Yes, then click Ok.
- Click Yes again when prompted with "Are you sure you want to perform these actions?"
- Disk Cleanup will remove the files and close automatically.
- On the Disk Cleanup tab, if the System Restore: Obsolete Data Stores entry is available remove them also.
- These are files that were created before Windows was reformatted or reinstalled. They are obsolete and you can delete them.
Microsoft KB article: How to turn off and turn on System Restore in Windows XP
Bert Kinney's site: All about Windows System Restore