| In order to download data you need to upload information. So if you
| saturate your upload then yes your download will go to a crawl.
Not according to my simple test here on W2K and a PCI modem. There is some impact, dropping from a normal 1250+ Kbps down to ~1100 Kbps down as a foreground process. I wouldn't exactly classify this as a crawl. The background process was a relatively long FTP upload, at full speed. The upload process shared the bandwidth between processes equally. I didn't test download in the background process since I would generally be more interested in the foreground process anyway.
Looking at the help file on foreground-background priority, I find that there is some slight amount of control on foreground-background processes as seen here... two options... however, I am not sure as to how this would apply to up/downloading.
To change the performance of foreground and background programs
1.. Open System in Control Panel.
2.. On the Advanced tab, click Performance Options.
3.. Under Application response, do one of the following:
a.. Click Applications to assign more processor resources to the foreground program than the background program.
b.. Click Background services to assign equal amounts of processor resources to all programs.
a.. To open a Control Panel item, click Start, point to Settings, click Control Panel, and then double-click the appropriate icon.
b.. Choosing the Applications option will result in a smoother, faster response time for your foreground program. If you want a background task, such as a Backup utility, to run faster, choose the Background services option.
c.. The Applications option allocates short, variable time slices, or quanta, to running programs, while the Background services option assigns long, fixed quanta
I don't know how this is going to display... hoping for the best.