Forgive me if this is answered somewhere else, but I have tried searching on the problem and am not coming up with any relevant results (anywhere on the web).
I have Vista 32 Ultimate installed on a P4 Quad Core with 2GB of ram and an onboard NIC (10/100). The HDD is 250 GB total split into 32 GB for C and ~220 on D. Neither drive C or D are over 50% full.
I don't download any music or movies, nor have I ever installed any download agents, software, or toolbars (such as BitTorrent, Gnutella, iTunes, Google, etc.). I only state that because I know some of those can be "running in the background" and cause network bandwidth to be used up.
The problem is that when I attempt to download files (using IE or Firefox) from seemingly any website, the download may randomly halt. The progress indicator bar just stops moving. The file copy / download animation is still running, but there is almost zero network or CPU activity reported in Task Manager. Also the percent of the file that is downloaded will also be random. (23%, 51%, 13%, etc). If I cancel and restart the download, sometimes it will go a bit further, sometimes it will actually download less before hanging. Sometimes if I cancel it and restart it enough times, the file download will complete (maybe).
The file sizes range anywhere from 1-3 MB (patches, drivers, etc.) all the way up to 2+ GB (downloadable game clients).
What I have done to attempt to track down the problem:
Disconnected my laptop and my wife's computer from the network, so that it is just my computer. (same problem)
When the file download "halts" I have opened IE or Firefox and am able to browse the web. I can even open WinAMP and listen to streaming media or play an online game.
I don't seem to have the problem if I download files using CoreFTP. I admit I don't use FTP that much, so that's a small test at best. I can download the same exact file from the same exact website at the same exact time using my laptop (Windows XP) and the laptop downloads the file just fine.
I have tried 3 different Anti-virus software and even uninstalled all anti-virus software. I have even re-installed windows clean (once) and I still seem to have the problem.
It does seem to be isolated to my computer so I suspect there is a windows process that is trying to "protect" me by scanning files that I download. But I don't know what that could be. Anyone have any suggestions for me to try that I haven't already thought of? This thing is really frustrating me.