Vista - SP2 is saying to install SP1 first, but SP1 is installed

Hello I have Vista Ultimate x64bit and trying to install SP2 Standalone onto my Dell latitude E6400 and is telling me to install SP1 first, but SP1 is installed.

Did anyone have simular problem, or suggestion on how to solve this issue? besides installing OS with SP2 included.

Thank you.

PS> I googled the S_it out of it, but no go.

A what you have phrases in HKLM\Software\Microsoft\Windows NT\CurrentVersion

I attached image below.How it looks by you?Show screen.

If “vLite” was used to customize your Windows Vista SP1 installation, you may have removed required system components which prevent Service Pack 2 from installing. See KB 968279 for additional details before installing Service Pack 2.

it says 6000

But then on that last line you made it red it says Sevice Pack 1

And when I try installing SP1 it says that SP1 is already installed.

And what about with phrases BuildLab,BuildLabEx -they should be have something +vistasp1
In my opinion with all these phrases:BuildLab,BuildLabEx,CurrentBuild,CurrendBuildNumber

should be appear number 6001

Please show screen from this key -it was screen from polish Vista and with english Vista can be difference -unfortunatly on my second computer where is english Vista SP2 is already installed.

Maybe you will have luck and will be enough only correct something in this key.If it fail as @Ex_Brit suggest you can try Repair Install For Vista

EDIT
Another solution could be uninstall SP1 (it is only possible if you never used vsp1cln tool) and install SP1 again