What causes the 'net to shut down?

A lot of times after a while or if I am doing something (like burning a DVD), the internet completely shuts down (I have to hard restart the cable modem, and disable/enable the device in network connections).

In a similar situation, it sometimes does not completely shut down, but rather continues to download in uTorrent but will not load web pages. Granted, at times the download speeds are exceeding 250kpbs, but sometimes this same situation occurs when it is downloading at something like 10 or 20kbps.

In yet another similar but not completely the same situation, the internet (downloading/web pages) does not shut down on my PC, but anything connecting over my wireless network will not load web pages.

I know they are probably all related to RAM, CPU usage, etc, but if someone could explain specifically what might be causing it that would be great.

My basic specs are:

XP Home
2GB PC3200 RAM
3gHz Prescott
Lite-on DVDRW
SATA HDs

 

Actually im more leaning towards torrents causing your problem. Torrents open a ton of connections, and can cause issues with three things. Firewalls that may be poorly built may not handle a large continous about of connections well, though thats unlikely. Second thing is the router, some common routers again dont' like large amounts of open connections. The last and third is utorrent using up all your bandwidth, thus shutting other connections out. I have seen it myself.