I'm not 100% sure either, but I think you could not mix and match cards as old as the X800s.

And do both drives have letters assigned to them? (C:, D:, etc.)

If one does not, can you right-click on that drive, select "Change Drive Letter and Path" , and give it a letter?

Its rather unusual that the 640GB drive won't appear in My Computer when Windows sees a healthy partition there.

It says "Healthy (System, Active, Primary Partition)" Is that whay you were looking for?

DA_muffin_man01

Yes. Does it say that for both the 400GB and 640GB drives?

And what does it show about the drive's partitions in the lower half of the Disk Management window?

Check your video card, too. You're not going to want to find out you have an incompatible AGP card while you put it all together.

Well, it means your modem and PC aren't connecting properly. Could be caused by a bad cable or a bad NIC on either your PC or the modem.

I don't quite see what your problem is. What do you mean Windows is not detecting the card properly? If you can play games at full detail just fine, you don't have a problem. And an ATI card will work fine on Nvidia motherboards and vice-versa (just no SLI or Crossfire)

If your problem is that Windows Update shows an ASUS video card update, let me help you out: NEVER rely on Windows Update for new drivers. Go to ATI or Nvidia or the part manufacturer to get the latest drivers. You can't help it if Windows Update misdetects your hardware, but you don't want their drivers anyway.

Tou could try turning on SMART in your system BIOS, see if that detects the possibly bad drive.

RTS games are heavily reliant on the CPU, -GeordiLaForge-

RAM too. Have you tried pulling up Task Manager to see where all your CPU utilization and RAM are going?

Does Windows even detect that anything has been plugged in? Might be the port.