.inf files are information files.
Normaly, the update.inf file should come bundled with the update package that need it, or have been automaticaly generated by a previous update.
You may have several update.inf files on your system, but they are ABSOLUTELY NOT interchaneable as they are application specific.
If the file is missing, it means that it was deleted from your computer. Some system cleaner are prety aggessive and will suppress those, even if they are still needed. Set any such utility to ignore *.inf files.
To correct the situation, you need to reinstall the whole game, then reapply the updates from the publisher.
If you have a cracked game, it may have been updated and an update.inf file generated but not included with the cracked distribution, or included but the original location and details don't match your actual location and details (details like the path of the user profile) making the update.inf file invalid. In this case, you are out of luck as it's not possible to recreate that file by hand.
Electro, July 2012
