It should be in the root of C.
You may need to install in IDE mode for XP to function, which will mess up Win7 if it's installed in AHCI. I don't know if you can reverse Change IDE to AHCI in BIOS - Much better performance - Windows 7 Forums
You should be able to find the LAN driver by googling the device make/model for an XP driver, if necessary tracing the Hardware Identification
Another option is to sort it further doing an XP Repair Install
since at this point it's experimental anyway.