Dell Clamshell desktop hard drive question

Where do they hide the harddrive?

I think I've found it via this link http://midwestitonline.com/wp-conte...in-a-Dell-Optiplex-GX260-Desktop-Computer.pdf
So
Got it out. Clamshell pc's are weird.

Is it possible to inexpensively replace a APL Maxtor DiamondMax 16 80GB ATA/133 HDD
with a ID Maxtor DiamondMax 10 Model ;6L 100P0 100 GB PATA133 HDD ??
1st one is from a Dell desktop. 2nd one is from a homemade tower,both are XP Pro OS's. TIA

I have not "forced" any connection, but I have connected the 2nd harddrive mentioned to the connectors & so far it went well.
No,I have not turned it on or booted it up & won't if it could/would/might damage anything which is why I'm asking before proceeding. Any thoughts? TIA

They are both IDE drives .It will work. http://support.dell.com/support/edocs/systems/opgx260/en/ug/sffdrvs.htm#1138128

This web site should help you get it set up in the bios If need be.

Thank you,I'll check out the link soon as I keep my fingers crossed & hope for the best.