Continous restart of windows

Well the problem you are facing its most common.. and it get mostly resolved by formatting but as you are thinking its the last option. so I think if you are using any branded system like Dell/HP/LG/Sony you must have diagnosis CD/DVD to check hardware or software level problem and if you are not having any CD/DVD you can download Norton system doctor/ any other hard disk bad sector checking software and also you can use Windows XP/Vista DVD to check hard disk bad sector error.. and also unplug unnecessary hardware like printer,scanner.. I mean just start your computer with basic hardware i.e. mouse and keyboard only.. and also one step you can do is.. go to your bios and check load default settings from your bios and reboot.. Hope this will solve your problem if not scan your system with bootable antivirus. you can find one by googling "portable antivirus" keep setup in pendrive and load it while booging. Last option as always format it.. Good Luck.

This is the basic solution i suggest for almost all such problems posted here on mylot. Just insert a Live CD of ubuntu OS in your CD drive and start your system after setting the boot device priority to CD drive. Then, get into ubuntu, then check for recently created files in system32 in [ C:\WINDOWS\system32 ]. If you can recognize the files [mostly, .exe files,] you can delete them. Also, check for such suspicious files in C:\WINDOWS. Also, check for some unwanted files in Documents and settings and also in the start up folder. [delete all in start up]. You may find C:\ drive in ubuntu at home/host.