How to repair Vista?

My problems have progressed from invalid/missing/corrupt icons:
http://tinyurl.com/2whpf7

to the Open and Save dialog boxes locking up any program that uses them, and
Explorer doing the same. Very limiting, since most applications load or save
files, or i sometimes want to see my computer.

i've tried System Restore.
i've tried sfc /scannow

All that's left is to try to repair my computer.

i've tried booting from the Windows Vista DVD, and selecting the "Repair My
Computer" option. Unfortunatly, the only choices availabe are:
Startup repair
System Restore
Windows Complete PC Restore
Windows Memory Diagnostic Tool
Command Prompt

None of these are for repairing a computer.

i read that if i try to install Vista in-place as an upgrade: my copy of
Vista will be dclared illegal.

So the question is how do i repair my computer?

Feature regression from Windows XP?