Can't install - "another version installed"...!

Now I can say that I hate Corel... Spent two days of my life just trying to install INSTALL!!!

Got a notebook with illegal copy of X7 on it. I have a fresh license of X8 (which eats HDD - another thread posted about this!) and old license of X6. Decided to install old X6 on this NB.

Two days with no success! Any ideas? Any special cleanup program???I did everything - uninstalling, cleaning by Revo Uninstall, cleaning the registery, cleaning, cleaning, cleaning - endless cleaning.

Uninstalling all other applications - shell extensions, MS Visio C++ all versions. Tried EVERYTHING but still "another version is already installed".

What to do???