Windows 7 apphang

So it starts out with Firefox causing an apphangB1. This snowballs until I cannot use any form of media. As in, once Firefox has caused an apphang, Windows Mediaplayer, Itunes, Flash, Photoshop, Image Gallery, and any other program including games will not run, at all. This happens to me literally every day. The only fix is rebooting. Luckily my computer restarts within a minute, but it is still a hassle.

I have looked up a number of fixes. Some forums say reinstall Flash. Doesn't work. Others say uninstall Flash, which of course limits my use of the internet. System restores are useless. I'll elaborate about that next.

When I bought the laptop (Dell XPS Studio 1640) in August, it was running Windows Vista 64-bit. For several months I ran that until I qualified for the free update to Windows 7. In this time, I never once had an apphang. Within a week of Windows 7 use, this problem emerged. I dealt with it, ran virus scans, nothing came up. Then I found that my harddrive disk arm was broken, so I sent in for a new one. Dell could not send me a hd with Windows 7 already on it, so I was given a Windows Vista hd. I installed Windows 7 from the disk again, and then started porting my music back onto the disk. I used IE this time, and guess what happened? apphangB1 snowballing into no media working.

The problem cannot be related to a virus, even when I had a brand new harddrive with only IE and some music, the apphang snowball started. Flash may still be the problem, I don't know. Anyways, this is persuading me to go back to Vista, a sentence I never thought I'd utter. No update from Microsoft seems to fix this, so if anyone knows how to help, I'd appreciate it. Thanks