Sorry, I can't replicate this issue, all I can do is make suggestions based on some previous posts.
Your error message should also be displayed in the Windows Event Log and may be more detailed:
From the
Control Panel->Administrative Tools->Event Viewer->Application (and/or System)
Follow the instructions in
this topic to download the Microsoft Visual C++ 2005 Redistributable Package (x86) which may help.
This post has another MS fix for MySQL
viewtopic.php?f=16&t=32617Also try adding
Win32DisableAcceptEx to the end of your httpd.conf file - has been known to fix some strange issues but usually only for Apache.
Sometimes other programs like the Firefox browser use port 3306 and fail to release it when finished with it.
Check using
xampp-portcheck.exe if that port is free - if it is being used by another program then close that program and wait up to 5 minutes or so for the system to close that port then try to stop MySQL after starting first it in your XCP.
There may be other responses to your issue that may give more details, but for now it would seem to be your XP that may be at fault especially after reinstalling XAMPP.
BTW does Apache start OK and can you get to the Welcome Page at
http://localhost and do the demos work?