Windows Vista Please advise. Install over current but other versionn

[MTHall51]

I could really use some good advice. Currently running Vista Ultimate, but no clue where my activation key is. Long story, but my system is cluttered with a lot of partially uninstalled apps. Now, I am seriously thinking of bidding on eBay for Win Vista Business. Questions:
1] If I don't have a bootable DVD, and simply installed Business right over the top of Vista Ultimate would that possibly cause a problem?
2] It has been so long since I tried to do a reformat or make a bootable DVD that I have forgotten how to do it. Anyone know of a good, detailed, tutorial on this?

Thanks very much.

 

[Celestra]

MT Hall 51--The product key is on a "Sticker" on your computer or located with the "Windows Product Manual". It is also encrypted in the "Registry"- Not readable and almost impossible to find. If you can't find it on a sticker or in the product manual I would recommend that you go with one of the top 6 free product key finder programs. Link Removed due to 404 Error

 

[kemical]

I could really use some good advice. Currently running Vista Ultimate, but no clue where my activation key is. Long story, but my system is cluttered with a lot of partially uninstalled apps. Now, I am seriously thinking of bidding on eBay for Win Vista Business. Questions:
1] If I don't have a bootable DVD, and simply installed Business right over the top of Vista Ultimate would that possibly cause a problem?
2] It has been so long since I tried to do a reformat or make a bootable DVD that I have forgotten how to do it. Anyone know of a good, detailed, tutorial on this?

Thanks very much.

As well as Celestras excellent advise I just wanted to add that.... yes you could install business over the top of Ultimate (whilst doing a reformat in the process) but ultimate is the superior edition. Try and keep it if you can..
As for guides.. Try this http://www.tweakguides.com/TGTC.html

 

[MTHall51]

Thanks very much everyone. You really saved the day. The key finder app worked beautifully and am very happy to say the reformat and re-install went great.