You do not have to install it, just unpack the ZIP and run yPortablWS.exe from there. If you're lost take a look at the How-to.
On the first run the Windows Firewall may ask you the permission for port-listening, click "YES", it's a webserver after all ;)
This seems to be a little issue with the Cygwin DLLs... I asked some other people for it, the answer is: take another try. It will work. You could try to stop MySQL too before starting Lighty again.
This PHP release has some issues on newer OSes (like Windows 7 and Vista) with the IPv6 support, and I didn't manage to get it runn flawlessly :(
Anyway If you know how to fix it, tell me!
Yes you are allowed to! Just please don't sell this!
Feel free to do so! But please do NOT redistribute the software without asking me.
I won't give much support on this. It's "free as a beer". But give it a try and email me if you want ;)