A friend's 18 month old PC was running very slowly and asked my help. The PC has Windows XP (with SP2) and they run Norton AV.
They regularly access the internet so firstly I installed AdAware. This detected over 700 "nasties" which we deleted. We then ran the online Norton virus check and this found over 400 files infected with 4 rogue diallers and around 4 viruses like adware.huntbar.
I followed the various Symantec removal instructions, including downloading and running the relevant removal tools. Some of the diallers were removed but after scanning (in Safe Mode) and checking the registry where directed by the Symantec removal document, there was no obvious evidence of the previously detected viruses.
I also downloaded Spybot and this found around 30 rogue entries, including reference to the diallers that were not evident (or had been deleted) in the prior removal attempt. We deleted these nasties.
The PC was certainly running much more quickly. However, we have since re-run the Symantec online virus check and still found over 300 infected files.
I would like to know if I need to still need to try to remove the alleged viruses/files or if the affected files can stay where they are?
Depends on the infection in the files and the files themselves. If they can recreate the bad stuff, (and it sounds like at least some of them have) they need to be deleted. If it was me I'd get the list of infected/affected files checked over and probably then get rid and be prepared to repair any damge this may cause at a later stage.