The one on the sticker on the pc.
It is the OS that came with the pc right? If so yes the sticker

The # on the side of your tower is the OEM license key. You may experience some difficulty trying to install an unlicensed version to this original system. If so, you might consider calling HP to seek their help in reloading the original XP Pro version...or repairing the one you have loaded. Once that's done you should be able to load the upgrades XP2 and 3 with no trouble.

The sticker on the side of my tower has an entirely different number.

That sticker is your serial number.
Look on the back of the tower. The sticker may be placed in an indent in the center of the tower like mine is.

Example:

{{gwi:1513140}}

Grandms for a repair install I do not think you get asked for the 25 digit key. However, be prepared to have the computer reject the CD as it is a different version than your media centre version. Certainly worth a try, the only thing lost will be time if you cannot complete the job.

As I have noted here before, any factory built computer can be wiped and the OS re-installed using any similar version OS but using the key attached to the computer casing. I have never tried using an XP Pro to install on an XP Home computer - and would not try the other way around. Once the hard drive is wiped there is no turning back so be prepared to instal Linux perhaps if your CD is rejected.

This is just so scary that I am not sure I want to even try the repair. I went to the other forum where the step by step instructions for doing this are given, and I find that there are many people who have no luck with this. I am still inclined to just use the recovery disks I made when the computer was new. I used them once, several years ago, and aside from re-installing programs and re-doing updates, it worked fine. I have detailed instructions from HP in literature that came with my computer for doing a restoration without losing data, and that's what I would do. Once I did this, then could I just use the SP2 update disk and then the SP3 update disk to bring it up to that point? I know I will still need to do 2 years' worth of updates since SP3, but I can do that slowly. I would use my Windows 7 machine until I got this one back up to date.

Also, what is the best way of saving my bookmarks and also my address book and the Saved folder in Outlook Express? All the rest of the e-mails can be accessed by browsing to Gmail.

Owbist, I wondered about using the Pro version for my Media Center OS, but BelArc and other apps keep calling it XP Professional, and that I never quite understood.

Boot up time seems normal, and everything else is working fine except the problems with SafeMode and SystemRestore as explained in my prior thread. But, Shutdown is taking forever----like 3 minutes or more. Once Windows finally shuts down, the computer powers off just fine.

Here is a link that might be useful: Blue Screen Message

Seems to me you could try the repair option and if that fails then you could use the recovery disks. That's what I would do anyway. You can export your bookmarks to a thumb drive or cd and then import them when you get restarted.

The causes for the problem are so varied...hardware as well as software...that if it were my equipment problem...I'd take it to a repair shop where the system can be tested beyond your home capabilities. If you kept an event log or can access the event log for the XP system...you might be able to go back to the day the event first took place and glean some repair info there. The system could need driver updates...or a new fan to prevent overheating...or more memory...or it contracted a "nasty"...or it could be as simple as deleting an offending program. IMO...the more you try to repair an unknown the more trouble you could get into. I think you must ask yourself whether it's worth jeopardizing the XP system.

in answer to can you use the sp2 then sp3 update cds yes you sure can but you must do them all in order sp1 sp2 and sp3 then you would have the remaining ones to do by batches. I just did this for a friend that needed help, it did not take that long once started. I had loaded all my programs on a thumbdrive so then just stuck that in and added from it my AV, various security programs, etc that I wanted on the pc all with out having to go online. Once it was ready I went online and got the various updates for the programs then windows updates by batch.

I would use xmarks to save your bookmarks just install xmarks now to it and any of your other computers and sync them it will put all your bookmarks on your own webpage also so you can access your bookmarks from anywhere if traveling or using some other pc. Then just install xmarks on the pc after reinstall and tell it to sync up and there you go all your book marks will be back. IT can also back up your profile if you want it to.

I can not help you with the other address book issues I do not use those

you will likely have a lot of that old junk to remove if you use the original discs so add pc decrapifier to your tools and also app remover if there was an old AV on there that would need to be gone.
PC Decrapifier

Using AppRemover

Putting everything on a thumbdrive is very handy and I keep one around never know when you have to help someone else. I luckily had it with me last weekend when I went to visit family, I had to use it to clean up my brother in laws laptop, he only had over 60 infections!!!

other wise to save your bookmarks you would go to (firefox) Bookmarks tab, then organize bookmarks, then at the top you will see Import and Backup, select that the select the export option save that file.

Here is a link that might be useful: xmarks

Thanks, RC. I downloaded the setups for PCDecrapifier and AppRemover to a flash drive and printed out the instructions for using AppRemover. I already had xmarks added to Firefox, but added it to IE and Chrome, too, just to make sure I've covered all bases.

I'm still not completely sure which path I'll take, but even though it will be more work probably, I'll feel more secure using the recovery disks I made. I think instead of trying to back up stuff to thumb drives, since I have so much, I'll use my EaseusToDo backup program to backup all my programs as well as documents, pictures, music, etc. Everything will be in one place on an external HDD where it will be easy to restore.

This project will probably wait until next week when I have more time, and who knows, maybe I'll change my mind about the method to use. My real concern with the repair using XP disk, is that no XP disk came with my computer, so using a different one might not work.

The point I tried to make above is that if the repair does work it would save you a lot of work and time. If it doesn't work I don't see any way it could keep you from using the recovery disks.

I agree with Bob but I do seem to remember that doing a repair requires the right CD, at least that was the case with my OEM CDs. You will know within minutes of attempting the repair so only a few minutes will be lost.

Okay. Thanks for this information.