Windows 2000 pro pagefile error

We took a drive from a machine that would not boot and added it as a second drive to an identical machine for the purposes of extracting data.

After taking it back out the machine we put it in will not log on now as it gets a pagefile error.

If we return the 2nd drive the machine boots. the drive that was put in to get data off came up as E: so I dont believe at restart it booted from it but im stumped.