I understand that the hard drive is ATA100, but the specs on the mobo say it is only compatable with 1 x ATA133 2 Dev. Max. Is that technically the same thing? Or do i have to get a new hard drive as well?
I'm tempted to say save thew 160 GB one for external storage but it would cost you close to $40 for an enclosure. But to answer your question the 133 MoBo should handle the drive, however do not attempt to put it in your new machine if it is a drive w/ an OS on it and you plan on booting from it.
ATA100 drive. No new system deserves that. The new SATA drives are so much faster, and they are not that expensive. But if you must, you must. Yes it will work fine on a ATA133 controller. That just means it will support up to that speed, any ATA drive 33/66/100/133 will work with that controller.
But as mentioned, if you load a modern OS on that drive as a boot drive, get used to turning the PC on, and then go take out the trash, wash the car, mow the front yard, then come back and it should be booted and ready to go by then. If you have an anti-virus program that does a startup scan, then go ahead and wash your wife's car, mow the back yard, till the garden, then come back in and see if it is ready to go.