clean partition from samsung?

[Bobo]

Samsung notebook rv145 WIN 7 4GB RAM AMD E350 1.6 chip 64 bit.ati 1gb video card. Problem i had a virus, couldnt remove it so did a samsung restore and wiped C drive reinstalled win 7 and did a NORTON full virus scan which found several trojans and removed them sucessfully. On a samsung it has its own built in recovery system partitioned off from the rest, i have since found out that its possible for a virus to cross partitions so even if i use the restore function it may well still be infected. i want to do a complete wipe of the drive including all partitions but that then leaves me without the drivers and os system as no one supplies a cd these days. Currently my icons are locked on the desktop, office keeps crashing, i cant move files or folders from one place to another, if i reboot it seems to fix the problem for a few minutes then it comes back, its driving me nuts. So any useful suggestions are welcome i have done all i can regarding malware and virus removal so it seems only option is to wipe entire HD which is partitioned into C and D drive and im assuming some extra space for the reinstallation of windows when a problem occurs, .When i first bought this computer a year ago new and booted it up, i had to reserve some 25gb for backup for OS and drivers etc its not shown if you look at C drive, meaning i can't see this reserved space only my C and D drives.. Thanks for any light you can shine on this