Downloader.trojan doesn't do much harm in its own right. What it does is download nastiness to your computer from the internet (hence I would guess it's presence in your Temp Internet Files).

Not an expert on viruses but I'd disconnect from the internet, reboot, run a full system check with Norton (are your virus definitions up to date?) and if Norton detects nothing wrong then assume the best.

Might also be worth doing a search of your hard-drive for any files named "downloader.trojan" and then deleting anything left.

If you're unsure whether your present scanner is giving the "right" answer or not you could try using a different one.

AVG is a free scanner which can be downloaded from http://www.grisoft.com

If you don't want to download and install a different scanner on to your PC you can always try this:-

http://housecall.trendmicro.com/housecall/start_corp.asp

This is a one-time scanner which runs inside your web browser (keeping out of the way of your existing scanner). There's a fairly hefty download (which could take 15-20 mins if you are on dial-up) first, but those people who have used this have found it to be a useful tool.

Staff note: I did try to get URLs authorised, but there was no-one available in the chat room. Given the nature of this subject, I felt it was wise to post my answer sooner rather than later

Thanks for that guys...I ran the scan that you recommended GS, and it didn't pick up on anything. I'm guessing that I got rid of it when I cleared out my Temporary Internet Files.

Thanks for all the help!