Vulcan,
Sorry, but I've never used Vista, although I don't believe the operating system would be the problem anyway. With respect to IE9, I'm not sure you can upgrade to IE10 while on Vista, but if you can, I would highly recommend it. Windows Firewall and Norton are probably not the problem either, but I use Microsoft Security Essentials for my anti-viral (free and fairly highly rated) and Comodo Free Firewall (although, if you look at my earlier post, I had to downgrade from version 7.0 back to version 6.3, to be able to upload pictures).
Most likely, the problem is in the add-ons or plug-ins. Look at them both and make written note of the ones that are currently active or activated. Then, deactivate or turn off all of them and see if you can upload a picture. If that works, then turn them back on, one at a time, from your written list and try to upload a picture after each one is turned on. Hopefully, you will find the one that causes the upload problem and then just leave that one turned off.
If that doesn't work, the problem is above my knowledge level, and I would recommend you try other browsers. I have IE10, Firefox, Chrome, Opera and Comodo Dragon installed on my Windows 7 computer and just switch browsers if a site gives me problems. Most times, the browser switch resolves the issue. By the way, the order listed is generally the order in which I do the switching.
Good luck,
Chuck
PS: There is a slight possibility that a firewall setting is causing the upload to crawl to the point it looks like its not working. You might want to check the Microsoft on-line help site to see if anybody else using Windows Firewall has reported upload issues and how they recommend fixing the issues.