A couple of days ago I installed the trial version of Photoshop CS5 extended onto my laptop. This afternoon I decided it was time to install it on my desktop system and give it a good look over

Win 7, 64 bit system.

Installation of the 64 bit version went without a hitch, but the 32 bit version falied to install (twice). I need the 32 bit version as well cause my Nik Software plugins do not work in the 64 bit version yet.

After much searching of the net and a phone call to Adobe we came across the solution. Even though my user account on my system had administrator access, for some reason it would not work. Adobe got me to create a new administrator called : Admin : change to that user and install. It worked straight away.

The error I was getting was :
WARNING: OS requirements not met for {7DFEBBA4-81E1-425B-BBAA-06E9E5BBD97E}

And for information there is an Abobe CS5 installation troubleshooting guide here : http://kb2.adobe.com/cps/829/cpsid_82942.html

This issue is being reported on the net on various forums and seems the solution is to have an Administrator account called Admin, and install from that user.