It can be found in the device manager, properties for the IDE or Sata controllers, most hard drives are UDMA 5 or 6 these days.

Thanks for the reply.  My Primary IDE channel is mode 5, and secondary is only mode 2.  Im not sure why they are different (?) but does this mean that if I am going to install another hard drive I should look for one that is ultra ata-100?  Thanks again for any help on this.

Mode 2 usually means a cd/dvd rom drive is installed on that channel. Yes ATA100, some are sold as ATA133 but there is no real difference between the two. 

Buy Seagate brand, they have a 5 year warranty.

Great, thank you very much.