cleaning hard drive

i need to clean my hard drive as i want to in stall win xp as my wins home edition has gone haywire (no desktop icons or bar )tried in task manager for explorer exe to temporary give me icons but it wasnt there ,my child has informed me she was playing about with my pc and was deleting wee folders as she put it ,so if anyone could point me in the direction of free and easy to use software for a clean wipe of a hard drive i would be grateful ,thanks

tried to open my other pc and got this c:\WINDOWS\system32\ctqyrmdv.dll in a box in the middle of the screen

 

http://majorgeeks.com/Free_Disk_Wipe_d5309.html
http://majorgeeks.com/Active_KillDisk_d4791.html

 

But, if she's going to wipe, i.e. format, the hard drive and reinstall Windows, why not just use the formatting option during the Windows installation? No need for special tools here, is there?

paul70, I suggest you create a limited user account, rather than an admin account, for your child to use. Put a password on your admin account so your child cannot access it.