Protect your computer
Check this Out[Works For Windows XP ,Vista]
This trick will help against Hackers & Viruses(Mostly for Viruses it is Helpful)
Caution: You must be Admin or must have Admin privileges
Step 1:
Go To “Folder Option” in “Control Panel” –>”View Tab”
Uncheck “Use Simple File Sharing” –> Apply & OK
Step 2:
Right Click on C: Drive(If Operating System is installed in C: drive) –> Properties.
You will see a new tab as “Security”, click on it .
Select User’s at “Group or user names” (you will see all permissions of users on C:Drive) –>Edit It As per your requirement(Suggestion: Uncheck Write Permission For All Users except Admin) & Apply it.