Apache / MySQL don't start

[freesitebuilder]

I'm running XAMPP Lite on XP Home SP2. I installed and ran it for several hours yesterday, but when I try to start today, I just get "Busy", then "Apache started", but the "running" icon doesn't appear, and the test pages don't work. Same for MySQL.

I've run the port check, and all ports show as free. I shut down Zone Alarm, but this made no difference. Windows firewall is not running. ZA settings when it's running are allowing Apache and XAMPP internet and server access, and it was running yesterday when I had no problems.

I'd be glad of any help on this - thanks.