Get ubuntu 10.10 on a CD/DVD
Put that in the PC
Go to C:/Windows/System32
remove Utilman.exe
copy CMd.exe and name the copy Utilman.exe
Restart PC
Got to the help guy (idk where it is but dont log in before)
Instead of help guy you get a Cmd with access to EVERYTHING ON THE PC.
Fool around with it
Change your account to admin
Delete registry
Except the problem that Ubuntu doesn't natively support NTFS
Use the SysInternals BSoD screensaver instead, much safer and you get an awesome reaction if you make it unexpected.
I used it one time as an April Fools joke to my brother by replacing Firefox.exe with an application that opens "C:\BSOD.scr -p", he freaked out and turned off the computer and came to me about the issue. I started saying random things, then I came out with the standard "April Fools!" He hits me and never forgave me