Computer freeze while downloading

Whenever I download a file from the internet, my computer completely freezes and sometimes restarts itself within a couple minutes. Most of the time I end up shutting it down manually.

It seems more likely to freeze if the file is large and if I'm using google chrome.

Specs:

Windows Home Premium 64bit
Intel i7 3770 3.4GHz
Radeon HD7870 GPU (Just bought it and installed the drivers)
8GB RAM
Antec 650 watt power supply
1TB hard drive



Thank you for the help!

Poimetheus said:

Could be a number of things. Try using a different web browser. If this leads to no avail, make sure the system isn't overheating. Also, how are you connecting to the net? (wireless, wired, type of NIC, etc...)

It's a wireless connection. It works well when I download something on my laptop which connects directly to the router, but my computer shouldn't crash just because of a slow connection, right?