You never said why the failed machine does not boot.

If it is because the hard drive boot or root file system is corrupted, then putting the drive in another machine as drive 2 is the only way to get data from the drive.

If some other component failed, such as the motherboard, then you can build another computer from any Pentium class machine just by installing the host adapter and the hard drive.

If the host adapter is integrated into the motherboard then you might consider removing the hard disk from the machine that works, and installing the disk from the failed machine, booting and backing up to tape or an ftp site.