Is an Optiplex GX260 Mini tower, (Pen. 4, 40gb HD and currently 512mb memory), compatible with (1 or 2) 500gb IDE hard drives installed? Will also be installing (2) 1gb memory.
The GX260 supports 2gb of RAM [2 x 1gb modules].
Yes, on the 500gb IDE hard drives, providing you have the latest BIOS version, with BIOS version A04, support for 48-bit LBA for hard drives larger than 137gb was added and have XP SP-1, or higher, not XP with a SP upgrade.