Rob Pomeroy:
Thanks for your post. In the past, I have successfully used the above-described process to reinstall the XP operating system, when a reinstall was determined to be necessary - but when the PC owner had lost or misplaced reinstallation disks. In these instances, I had no problems using a full O/S (non-OEM) disk to reinstall from, but using the original OEM product key for the installation. Again, the only purpose for this process is get around the fact that I have no O/S reinstallation disk - which gives me no alternative but to do a factory restore operation in lieu of a clean install of Vista.
It was probably not clear from my original post - but my plan was not to purchase another license for Vista Home Premium - rather to try to locate and buy a used Vista disk (with or without the COA) to use only for reinstallation purposes and, as stated above, using my original product key for the reinstall.
Thanks again for your post.