A/V retro-active?

[bif_knows_zero]

Hello,

If I install a new anti-virus on my old pc, will the a/v pick up old virus' that were there before I installed the a/v? Or does the anti-virus have to be installed first to take them out?

Thanks

 

[ceewi1]

It will certainly attempt to do so, although it may not be able to successfully remove them. A few infections will even prevent the antivirus from installing in the first place.

Do you suspect that your system is infected? Installing an antivirus program is an important step, but you may also want to post a HijackThis log so that we can remove any active malware.

To post a HijackThis log, download the HijackThis installer from http://www.trendsecure.com/portal/en-US/threat_analytics/HJTInstall.exe.

Run the installer and choose Install, indicating that you accept the licence agreement. The installer will place a shortcut on your desktop and launch HijackThis.

Click Do a system scan and save a logfile

When the Notepad window opens choose Edit -> Select All to select the entire log, and copy and paste the log into a reply post.
Most of what it lists will be harmless or even essential, don't fix anything yet.

 

[bif_knows_zero]

I don't think it's infected at the moment but it's been acting weird for a while now. It's a really old HP (circa 2000ish) that's had virus' in the past and some very helpful people here help me wipe them out after I posted a HJT log a month or so ago...
The current problem is that my wife went to click on the current A/V to run a scan manually and somehow accidentally clicked "uninstall". I was able to stop the uninstall, but did loose some of the program as now I can't start it. It was a really crappy A/V (The Shield) anyways so I was going to switch to AVG for free, I was just wondering the AVG might find something the old one didn't.
Sounds like I should try it out.

Thanks for the response!