Uploading freezes computer

Whenever I try to upload any sort of file to my email or another website, RAM usage spikes and my computer freezes up (obviously the cause of high RAM usage). I have 2GB ram and an Core 2 Duo E6550 overclocked to 2.6GHz ; this shouldn't happen. In fact, it doesn't happen on my other rig which runs XP on a similar configuration. Any solutions? Thanks.

John Doe

Windows Vista Ultimate 32-bit
Core 2 Duo E6550
2GB Corsair Dominator TWIN2X-8500
EVGA e-Geforce 9600

Go to Device Manager, Network Adapter and uninstall the NIC (network adapter); make sure you select to delete software and driver for that device. Reboot and let windows install a new driver. That should work.

@Andr0med: A riddle for you; how would Vista be able to search for a new driver when you just broke your connection to the internet by removing the network driver in the first place.