I assume Unreal was working before, without the patch upgrade?
I guess your problem could be caused by any number of things, so I think you're going to have to take this a step at a time.
First of all, did Unreal work without the patch? If it did, I suggest you completely uninstall and reinstall the original game without any patches, and see if that works. Also try going online and see if it works. If it works in SP but not MP, the problem may be with the server you are connecting to, and you should contact them for advice.
If it does work, there's a 90 per cent chance your problem lies solely with the patch you used - perhaps there was an error in the version you downloaded. Try downloading the patch again and reinstalling it and see what happens. Again, try SP and MP.
If your problem is still evident, there may be a conflict somewhere on your computer system. What's the latest version of Direct X you installed? Have you installed any other games or programs prior to Unreal not working? How often do you defrag your hard disk?
Have you checked under your system settings via the control panel to check that there are no hardware conflicts on your system? Have you installed any new hardware recently - perhaps there's a problem with the drivers.
That's all I can think of for the moment. What are the specs of your machine, btw?
'The enemy can't press a button if you disable his hand...Medic!' (Starship Troopers)