nother way to fix this in Windows (XP in this case) is to do the following:
* Open up Windows Explorer (Windows Key + E).
* Selects Tools -> Folder Options from the main menu at the top of the window.
* In the dialog, select the File Types tab (should be the 2nd or 3rd tab).
* In the list of registered file types, look for UT4MOD. If you do not find it, create it by clicking on New. Enter "UT4MOD" as the file extension anc click OK.
* Once it is in the list, select it and click on Advanced.
* You should see an action called "Install this UT2004 module". If you don't, click on New. Enter "&Install this UT2004 module" as the action. If it is there, click on Edit... .
* In either case, there will an option to enter an application to start the UT4MOD with. Click on Browse... .
* In the file dialog, find the Setup.exe in your UT2004\System folder. Select it and click OK.
* Once back on the action dialog, make sure that the filename has quotes around it. Then add the following at the end of the line: install "%1" (include the quotes and a space before the word install).
* The whole line should look something like this: "E:\Program Files\UT2004\System\Setup.exe" install "%1" . Once you enter the last part, click OK twice and Close to return to Windows Explorer.
That should allow you to double click on the UT4MOD and have it run correctly. Make sure you have quotes around both the setup.exe filename and the "%1". Without them, this will fail. I hope this helps.