Rebooting my computer to get rid of viruses?

my computer has beome increasingly slow over the past month or so, so i did a few scans for viruses and found that it is infected with quite a few different adware, spyware and trojan thingies. i have tried about 20 different scanning processes but nothing seems to be removing them. scanners from online find hem, but then won't remove them unless i register and pay!

i've been told that even if i do mannage to delete them i will still have problems, is this true??

is there a way to rebootmy computer to just remove everything and start fresh? if so will i still have windows XP or will it literally get rid of everything? i don't have a windows XP disk to re install it because the computer came with it on, has anyone got any suggestions o had imilar problems??

many thanks

Rebooting my computer to get rid of viruses?spyware remove

Free - For starters, download, update and run a full scan using SuperAntiSpyware (SAS) http://www.superantispyware.com/

SAS is an exceptionally easy to use application that will remove the majority of difficult Trojans and Worms, not just the easy ones. In addition it has the ability to remove Vundo and Smitfraud infections. SAS can lock your home page to prevent browser hi-jacking attempts.

If possible it is recommended that you load SAS in normal mode but run it in Safe Mode. Safe Mode can be started by continually pressing F8 during the boot sequence. If you are badly infected you might need to run SAS more than once to help clean your system. Afterwards if the only infections now being shown are in System Restore, once you are completely satisfied that you can boot normally, you can either delete the infected restore points manually, or temporarily turn off System Restore to purge the files.