... they specifically advertised for IDE ATA100 ID cable wires or ATA 133 (and so do many online websites)
Ouch!! Sad buggers ... somewhere someone is mixing up their terminology.
ATA is associated with the hard drive, not the cable ... IDE 100/133
cables really are the same.
Current ATA hard drives use the ATA/100 and ATA/133 specs, which are limited to transfer rates of 100 and 133MB/sec, respectively. They use the same IDE cable, an 80 cond' cable.
The 'older' ATA 33/66, and older ATAPI (CDRom/Optical drives) could,
did, use the 'older' 40 cond' cable. With the advent of the new speed of ATA to 100/133 required using/needing a better cable to carry the data.
There is a cliche to all that ... a 7200rpm HD will struggle to offer even 100MB/sec.
Just to throw a spanner in the works, if your system has SATA2, then I, and many here, would have advocated investing in a SATA2 drive.
You ain't as green as I read you are ... sorry, that sounds condescending, not meant to be.
What is the spec' of your PC, I'm mainly interested in the motherboard, the make / model will do.