Disk Read Error

Having a problem with a Dimension 8200 system with windows 2000. It was working fine. Then I took it for a 2.5 hour drive up Interstate 5 to another of our offices. Once there, I hooked it up and it still was working fine. I then installed the WordPerfect 2000 suite, and plugged in a USB card reader that has 4 different card slots and uses 4 drive letters. When I first plugged it in, it chose all drive letters that weren't already in use (local and network drives). I did a reboot after this, still fine. I left after that. The employee using it turned it on the next morning and it was still OK. After several hours use she was working with Excel when the machine completely froze. They had to hold the power button to turn it off. After that, when you turn it on, right after the Dell bios screen, it gives a "Disk read error occured, press ctrl-alt-del" and restarting just returns you to that message.
I told someone in the office to open the case up and check the wire connections to the computer. That didn't help. Then I told him to press F2 to go into the bios, had him highligh primary master and hit enter, and it still listed the WDC... hard drive model name in there so it seems like the BIOS still recognizes the drive.

I am wondering if the car ride killed the hard drive maybe? I had it laying on its side in the back seat. Though if that's the case I wonder why I didn't see this error right after hooking it up there.