Go to www.sysinternals.com
and under Process Utilities, look for Process monitor. Download, unzip and run it, then run the VRS installer up until it errors out.
Switch back to the process monitor, click the icon that looks like a little magnifying glass so it stops recording new events. Click the little icon that looks like a funnel so it brings up the filter selections.
From the filter selection, choose the following
Result is ACCESS DENIED
(Italics are the dropdowns, Bold is typed yourself)
Hit Add, then Apply.
You should then have a list of places where the installation errored out because you don't have access.