The latest official patch is 1.05, the patch is cumulative, that is it contain all the fixes from the previous patches and is the one to install.
It also strongly suggested that you install 1.05C over top of 1.05.
So Install the game, the DL and run the 1.05 patch.
Then DL 1.05C. this tweek pack is slightly different. it is a zip file that must be unziped into the HOI folder.
1) Select keep directory/folder structure if that is an option in the program you use to extact the zip.
2) select overwrite files when prompted.
It also strongly suggested that you install 1.05C over top of 1.05.
So Install the game, the DL and run the 1.05 patch.
Then DL 1.05C. this tweek pack is slightly different. it is a zip file that must be unziped into the HOI folder.
1) Select keep directory/folder structure if that is an option in the program you use to extact the zip.
2) select overwrite files when prompted.