On my Dell Inspiron 1501 laptop with Vista (SP1 although the problem was present before I upgraded to it), I'm having a big problem that whenever I'm downloading anything (through cable or wireless), any form of sound (music, movies, system sounds) from the computer becomes heavily distorted and my computer performance in general also slows at higher download speeds (10mbps). The distortion increases as the downloading speed goes up. By downloading I mean any internet activity i.e. downloading files or even regular browsing, until the page has fully loaded. This does mean that on live streaming feeds the sound is continually distorted as it is always downloading whilst playing.
Key points to consider -
Other intense system activity which is not related to downloading (i.e. copying large files, running installations or conversions) doesn't cause these problems.
There are no restore points that precede this as it has been happening for a long time.
I have a separate PCI-E sound card and using that, the problem still persists.
I have the latest sound card and motherboard drivers.
I have tried various media players/codecs and they all have problems with playback.
Any help would be appreciated, thanks.