WinVista error: Unsupported Operating System ( x86)

Hi,
I tried WSUS because Windows Update seems to be stuck in a Check for Updates loop, doing it for hours with no result. Additionally, though some updates were installed previously, Update insists the computer has never checked for updates before.
Downloaded the latest WSUS, ticked all needed boxes, ran update but got Unsupported Operating System ( x86) error.
I'm running Vista SP2 32bit on an old Toshiba, system restored in late May, latest update Windows Update Agent 7.6.7600.256
If relevant: tried to reset Windows Update components as shown here, got error while trying to run "net stop appidsvc", service seems to not be installed at all.
I tried WSUS because Windows Update seems to be stuck in a Check for Updates loop, doing it for hours with no result. Additionally, though some updates were installed previously, Update insists the computer has never checked for updates before.
Downloaded the latest WSUS, ticked all needed boxes, ran update but got Unsupported Operating System ( x86) error.
I'm running Vista SP2 32bit on an old Toshiba, system restored in late May, latest update Windows Update Agent 7.6.7600.256
If relevant: tried to reset Windows Update components as shown here, got error while trying to run "net stop appidsvc", service seems to not be installed at all.