I have had several problems when trying to upgrade Operation flashpoint from 1.0 to 1.20. I managed finally with this already cracked upgrade: OFP_120_fixed_update.zip and you can find it here:
http://tannen.cs.curtin.edu.au/nazz/opflash120/
You have to have version 1.00 installed with original no-cracked-exe. If you still have problem installing it you might have to try another computer cause it worked for me
