I am in the process of cleaning up my home system, and I just got the Service Pack 3 and decided to up-grade from SP2.
Well, I had no problems. I have 2 drives – one for windows and programs – the other is all my data.
First think I did was make a clone of my Windows drive and stuck it on an extra drive (I used Norton Clone to do this).
Then I ran the Service Pack, and it took about 35 minutes and was done.
Computer run fine, can’t tell any difference.