Hi Dave R, thanks for you help.
I've spent the day of yesterday looking through any windows registry keys but I haven't found any reference to sketchup (I've also used the search tool). I was pretty sure that any sketchup related keys were deleted (I've run a second registry cleaner just for the sake of it), but is pretty obvious that there is still one nested somewhere.
If you can recall which key should be deleted, please let me know!

I've spend the day of yesterday deleting keys one by one and I have a recovery point so I'm open to any suggestion

Thank for all the replies.

Dave R, yes I've run ccleaner registry cleaner several times both with windows in normal and safe mode.
I've also tried to re-install sketchup pro but it says is already installed where all the folders and the keys in the register were deleted....
I'm stuck in a endless circle...

Dear All,

I've recently installed the latest built of Sketchup8 pro and after the trial period expired I wanted to install the free version.
I did follow the normal procedure (control panel - unistall, etc..) to remove the pro version and when I started to install the free one a message prompted saying that where was already a version of sketchup installed on my system and I have to remove it prior installing a new one.
Here my problems began... I tried to repeat the process to remove the software and restarted the machine and it didn't work. I brutally deleted all the sketchup related folders and deleted all the keys on the windows register and restarted the computer and it didn't work. I've used CCleaner to fix any issues.... and didn't work.
I have virtually removed all the stuff related to sketchup but is still installed (it's like a virus I would say ). Before format the entire system, do you have any suggestion? I'm really open to any advice.

Thanks for any help

Ps: I'm using Windows 7