Many people knows this. I guess the people at Alwil also knows this. But people tend to try to solve problems with their own OS in mind. Normally this isn’t much of a problem, but in cases like this (XP home vs XP Pro) there are some (small) differences which one easy forgets.

I remember a call from someone who is in the same business like me. He said he had a system with a MS sticker on the site (XP key) and it corresponded with the key entered in the installation, but still some things where lacking and he couldn’t get them enabled. At first he thought he had found some rare illegal version of Windows Pro. So he asked me to have a look. He forgot that Windows was installed on FAT32. ‘Problem’ solved by me within 5 minutes ;D