Reset the CMOS: Clear CMOS - 3 Ways to Clear the CMOS - Reset BIOs
Wipe the target HD and create a 100gb install partition following the steps given here: SSD - HDD Optimize for Windows Reinstallation
Boot the Win7 DVD to attempt install to target partition. Unplug all other HD's and peripherals. Use PS2 mouse and keyboard.
If this fails, try install from XP desktop to target HD.
If these all fail, enter BIOS setup to set SATA controller to AHCI, try install to target HD plugged alone. If this works you'll have to set it back to IDE to boot XP.