[Buu]

Hello. Excuse me if this question has been answered tons of times already but I'm very unsure on how I shall do this.

To come straight to the point, I think my external 1TB HDD is infected with one or more trojan virus(es) and a few other ones. I was downloading a few videos when -upon opening one- Internet Explorer automatically started up itself with an ad.

So I became suspicious and decided to run the AVG 9.0 antivirus that detected three viruses which were deleted afterwards when the scan finished. I thought everything was fine then and plugged in my external HDD to save a few things onto it, not including the downloaded video mentioned before.

I unplugged it and continued with my usual activities on the laptop when suddenly Internet Explorer and Firefox opened themselves again and new advertisements showed up.

I scanned with AVG again, with no viruses found as result. So I went to Google and tried to get something different and eventually stumbled upon 'Spyware Doctor'. I installed it, let it scan my laptop and 29 infected files were found. Due to registration needed to let it delete the viruses, I had to get something different and ended up with 'Malwarebytes's Anti-Malware'. I started running it until it got to the folder location 'Spyware Doctor' found lots of viruses from. 'Malwarebyte's Anti-Malware' didn't detect anything in it though.

I got a bit nervous and shut down the laptop. Today I decided to reinstall Windows Vista by putting in the Recovery Disc and running it. Everything installed properly. I activated the 'Norton Internet Security' antivirus, scanned my laptop, nothing found. Then I proceeded onto 'Spyware Doctor' and it didn't find anything either. I uninstalled it and installed 'Ad-Aware'. Nothing was found. Then 'Malwarebytes' Anti-Malware'. Nothing either.

I guess my laptop is clean now but I'm afraid my HDD isn't and I'm unsure about plugging it in reading that the viruses can simply jump over from the HDD to the laptop.

I'd need some professional help on how to get my HDD clean from viruses, preferably without having to format it or anything similar that gets rid of all files from it.

I appreciate every help I can get. Thanks in advance.
-- Buu