HELP!! USB harddrive crashing out explorer.exe

[5vz-fe]

Guys, need your help........dying here.

Just got a Asus A8N-E motherboard w/ 3800+ x2 dual core CPU, installed W2K Advance Server. Pluging in my thumbdrive is fine, I can dump stuff in as well as take stuff out, but when I put in my USB 2.5" harddrive, it recongnizes it, but when clicking into it, it hangs the explorer.exe and the reading light on the drive turn from green to red...........

2.5" drive fine on my laptop.