In 20 yrs of fiddling with computers, I've never been this stuck!
Toshiba laptop with W7 64bit given to me to sort out 'a few problem'. First, it kept trying to install SP1, but failed every day. I have overcome that by burning SP1 to disk and installing from there.
Chrome icon has a blue/yellow shield on the bottom right quarter (like the UAC shield). Chrome will not open a page (with or without UAC turned on - if it is on, it asks for administrator approval, but still doesn't load a page). Have uninstalled with revo then reinstalled - same.
Flash player won't install - says initiallising, then stops.
I have run:
CCleaner, Combofix, MBAM, Hitmanpro, sfc /scannow, turned off AVG.
Some progress. After fiddling with Chrome settings, it will now open a page. The only thing left is that shield which (I now know) means it needs admin privileges to open. So, there must be a computer setting which is driving that. Had a look at the user acct control, and there doesn't seem to be anything there.