Core .2 and Doomsday 1.2

[Castellon]

You need to uninstall both, since mods like CORE are not supported.
Install vanilla versios and then patch DD with 1.2 and HOI2 with latest pach.

 

[Castellon]

Don't install CORE.
Patch DD to 1.2 then install and patch HOI2.
Then when it all works, you can install user mods.

 

[Castellon]

If you patch your DD BEFORE you install your HOI2, then obviously it cannot install to your HOI2 folder.
You could also change the registry entry , or zip the HOI2 folder or even rename it then install the patch and then revert to the correct name.

 

[Castellon]

Don't install CORE.
Patch DD to 1.2 then install and patch HOI2.
Then when it all works, you can install user mods.

I do not see anything in there about patching to 1.1
Did you try installing patch 1.2 before 1.1
1.2 is designed to be patched over a clean install.
Where was the DD installed to? what drive and what path?
Did your install of DD from the CD create a registry entry?
Did you search to see if there is a registry entry for regular HOI2 still in the registry?

 

[Castellon]

My advice was to patch from fresh install.

 

[Castellon]

Some that ran into that situation could patch 1.0 to 1.2 but not 1.1 to 1.2

 

[Castellon]

Check the Manual uninstall thread for how to delete registry entries.