HP has this BD player (HP TouchSmart DVD), which was installed on my PC when I bought it and this update.

I'd like to install it on other other PCs, however the installer has to check the PC manufacturer or so in order to verify it's a legit HP, otherwise installation process is aborted.

Can anyone help me sorting it out?

The easy part is to extract the file with WinRAR/7-zip/etc and navigate through the "src" folder, which contain the main installer (setup.exe, Data1.cab, etc).
I believe the whole process needs changes in other .bat files in upper directories, but I can handle those easily once the setup works.

As you may notices, this piece of software is made by Cyberlink and most likely will suggest me "install PowerDVD!". I'd usually agree, however this HP versions is the only one I found so far which is able to play Star Wars BDs flawlessly. Besides, something's telling me there is no region change limit, which is very interesting feature (yet to be confirmed).

My experience with it comes mostly from repackaging applications for automated deployment, but I can tell you that this could potentially be very difficult.  I don't expect anyone will be able to give you simple instructions, at least not without examining the software package first.  I will take a look at it, but no promises.

Checks of this type are usually a "custom action" -- a script or small executable is extracted and run by the installer. Depending on its exit code, the check is considered passed or not.

I should also note that the install time check may be just the first check and a courtesy measure to keep you from installing something that won't work.  It is quite likely that there also is a run time check.  Even if you get around the install check and install it, it may refuse to run.  Software vendors whose primary business model is bundling their product with hardware tend to be diligent making sure it can't be used without the right stuff.

Wow, that sounds way more complex than I could imagine.

I don't remember how, but I could extract all the files where they were supposed to be executing the .msi file with an argument (which?), but I believe all the registry keys were missing, therefore it couldn't work.

Whatever... I feel like giving up on this. I don't think it's worth the effort, then.