Windows locks up during upload?

Ive got this really odd problem. Every time Im uploading something, for more than a few minutes, my computer TOTALLY locks up. As in frozen on the same screen, cant move the mouse, nothing (if i have music playing, it repeats the same half second or so part it jammed on over and over). For a while I thought it was just a problem with Azureus. But it just happened a few days ago while using CoreFTP. So it must be a problem with uploading in general. I’ve never had a problem like this before, and want to know if anyone has any advice or suggestions on how to remedy it?
Im running WinXP SP2, and connecting to the internet through a WRT54G Linksys Wireless Router, and a Zonet zew2500P external antenna. Ive been using the same internet setup for about 3 years now and havent had any troubles like this. My computer is about a year old, and this problem just started a few weeks ago, and I havent made any recent hardware changes except a RAM upgrade, which i doubt would affect anything.

Anyone have any ideas?

driver

Check the event viewer and lan settings.

Don’t be so quick to dismiss the new ram,You should double check the spec on the ram you bought and the ram the board will handle.

bean55

Look over this:

run memtest86 if concerned about the ram