XP Home to Pro Re-format or not?

[gospel]

I'm going to upgrade from XP Home SP2 to Pro SP3. I upgraded from Home SP1 to SP2 and the results were not very good. Everything works fine but the bootup and shutdown times are much slower. The company I worked for went out of business and one of the things we all got out of the deal is a XP Pro SP3 disk and license. I am going to upgrade to it and was wondering if it would be best to do a complete reformat or just install it as an upgrade?

 

[KSoD]

You will have to do a format. I dont even think there is a option to upgrade from XP Home to XP Pro with a CD....

But you will be better off formatting. Upgrades are tenious at best. If there is any issues with your machine right now that will carry over. Best to start fresh.