Which XP?
 

I'm going to wipe out my laptop and put XP back on it. Stupid Vista really pi$$ed me off.
Its a tablet, so I would think Tablet XP is the best, BUT
I got a spare license of XP Pro from the office I can use.
or is XP Media Center good?

Which version?

For XP you really need the tablet edition to be able to use any of the tablet functionality. I don't think you have too much choice there. It is basically XP Pro plus the tablet interface drivers.

I wouldn't bother with MCE at all.

Tablet is the way to go.

Vista has tablet support in all versions, but for XP you'll need the dedicated tablet edition to have any use of the tablet in your machine.

Cool, Ill go with tablet.
And I got a new harddrive so I dont need to really back up anything on my laptop, I can just pop it in those notebook external harddrive cases.
Would I be able to acess my documents and desktop items from the hard drive (security rights) or should I copy all those files to C: before hand?

Since it is a tablet pc, I highly recommend Vista over the previous versions. Having progressed through XP Tablet Edition, Tablet Edition 2005 (XP SP2) and Vista, each upgrade was a giant leap over the previous one in usability.

If your tablet pc came with Vista Business or Ultimate, you have downgrade rights to XP Tablet PC Edition. Otherwise, there is no legal way to obtain XP Tablet PC Edition if your computer didn't come with it. Microsoft released XP Tablet PC Edition only as OEM-installed product. They are not sold through stores.

But Vista is horrible, at least for my laptop. Slow, using a lot of resources...

Sounds like something is wrong with it then. Was it a clean install? I'm running it on an 800MHz Samsung tablet and it runs perfectly smooth with no more than 4% cpu util. What kind of machine is it? And which processes are using the resources?

Do some googling about optimizing vista. By turning off lots of services, all the silly transitions & special effects, AERO etc. you may find Vista runs fine.

Here's one site I found in about ten seconds:

http://tweakhound.com/vista/tweakguide/index.htm

If that doesn't help, then consider the OS downgrade.

In my experience, Vista by itself is pretty fast. It slows down drastically depending on which applications are installed. The worst offenders were Norton or McAfee. I usually replace them with a lighter weight virus scanner like AVG.

Vista runs just fine on my 2003 vintage tablet, after I worked around Vista's initial reluctance to install on old hardware. It has 1 GHz Pentium M, but I typically run it at 600 MHz to extend battery life.