Should work fine. Just make sure you are booting off the correct drive. Vista may put its boot files on the first primary partition on the first hard disk, which could be your current master hard disk. In that case you will have to set your BIOS to boot from that disk, and not the one Vista is installed on.
TheMajorMMX - Intel P200 MMX @ 225Mhz - V-Tech (PcPartner) Baby-AT mb w/ Intel Triton TX chipset - Nvidia Riva TNT2 M64 w/ 16MB - 256MB M-Tec SDRAM - Still running.....