I am running Windows Vista on a Dell Inspirion that I bought in June 08. Everything worked fine on my computer up until about 2 weeks ago. I didn't change anything, add any new programs, nothing like that that would explain why I'm having issues now. I have Mozilla Firefox and IE7 installed on my computer. The problem is, I try to download something, even save a picture, and as soon as the download is done, it disappears from the folder I downloaded it to, and can't be found anywhere on the computer. In both Firefox and IE I have it set up so that files get downloaded to My Documents. This problem started of nowhere and for no apparent reason. I thought maybe the issue was in Firefox, so I tried downloading something in IE and I run into the same problem in IE. I even tried reinstalling Firefox and IE to see if that would fix the problem, but it didn't. Please advise on what I can do, Thank you!

Try downloading something to the desktop?

I would also scan your PC for malware... just to make sure (Malwarebytes.org)