I had problems too. even with a perfectly clean install.

So,,, after trawling the net for some cryptic solutions and then discovering Sapi's guide here anyway :O https://forums.totalwar.org/vb/showthread.php?t=84698

I came up with a good fast guide myself due to getting confused about patches also because there are a few apparently:

1. Defrag your drive prior to installing the game.
2. Install the game ( Do Not Modify anything! text files whatever!)
3. Defrag your drive again.
4. Install patch version 1.02 ( You Do Not need to install 1.1 first... Hey, it took me close to an hour to find this out) Also, the executable one works for sure. Some people reported problems with the zipped version.

The patch should take at least 14 mins + to install unless you have a serious cpu or something.

My method for defragging:
To defrag close all applications that are running, disconnect from net (Just pull the plug), exit all progs in task bar, then; Control panel>Performance and Maintenance>ReArrange Items on Your Hard Disk...


I know some would find this pointless to post but if it can save a new player hours of trawling the net then why not.