Overview:
CasinoOnNet is a gambling system which installs spyware on your system. The spyware collects personally identifiable information which is sold to third parties. They are one of the largest online casino's. If you're into that kind of thing these guys are one of the more trusted in that market. Unless you're a dedicated gambler you should remove this. Advertisements are also shown to you while you play the games.

There is an uninstall option in add/remove called Casino On Net.

End Processes (may or may not exist):
biuninst.exe
casino.exe
casinoonnet.exe
dlhelperexe.exe
downloadinstaller.exe

Unregister DLLs:
Tip: this is only a list of known files/locations. You will want to do a search by the name of the file to see if they're on your system.
A while back I wrote a guide to Register/remove DLL or AX files which you will need if you don't know how to unregister these files.

Each file is in several locations so you'll need to search for them and unregister + delete them in every location you find.

bszip.dll
mmi.dll
shared_.dll
sounddrv.dll

Remove Directories:
Program Files\casinoonnet

Clean your Registry:

You should be back to normal IF this was your only problem. I suggest you post in our HJT forum since its not likely that this is your only bug. Read this first