Moving XP Installation

Hello,

Yesterday my PC just randomly shut off after apparently overheating. It is my main business computer and I have to get it up and running as soon as possible. There isn't enough time to get parts before it has to be running. It looks like the MoBo and chip are toast.

I have another system that I purchased as a backup sitting in the corner. Both PC's are Dell's but are different models containing different hardware. My problem begins with the OEM installation of XP on the original HDD.

I would like to move the old, functioning, HDD to the new PC and perform a repair installation, but my understanding is that it won't work because XP is an OEM installation that is married to the old motherboard. If both systems are Dell's, but separated by a couple years, will it work?

If not, could I go out and buy a retail copy of XP, provided I can still get my hands on one, and would that work to repair my OEM installation? I would go through the process of starting from scratch, but some of my purchased programs are custom designed. The problem is that the company sends out a tech to install the program, but don't give you a disk. If anything ever needs reinstalled, you have to wait for the tech to come out and reinstall the program.

I talked to the tech today and he said he wouldn't be able to come out until next Wednesday, but I can absolutely not wait until then to get this up and running.

I also have a bootable DVD image I created using the Genie-Soft backup manager's disaster recovery routine, but I'm thinking it wouldn't work in the new PC because of the OEM installation. I have contacted their tech support but I'm awaiting a response.

Does anyone have any ideas? The big problem here is that one particular program. It's imperative I have this running by Saturday afternoon, or things are really going to hit the fan. And all this time I thought I was protected. I did everything imaginable such as secondary HDD's for daily backups, disaster recovery DVD's, off site backup storage and having a spare PC. Only today did I find out that none of that matters if you are dealing with an OEM installation of XP.

Sorry for the long post, but I wanted to explain things as thoroughly as possible. Any help would be appreciated. Thanks!