I know this is pretty basic, but just check to make sure that you have the newest version, that you do NOT have any filters on which would block the servers, and make sure that you have Crysis Wars/MW:LL listed as an exception in your firewall, etc.
These are some of the more common reasons that people cannot find a server.
If you've done all of this and it is still not working then you'll have to wait for someone with more technical expertise than myself to respond.
Sorry I can't be of more help
