Installs fine but does not work

[Verne]

When I click RUN SCAN NOW nothing happens, no matter which
options are selected. The background goes blank. Task
Manager shows that the program is running, but even after
several hours last scan run area says that I have not run a
scan yet.

 

[Engel]

Try an update install to see if this fixes the issue:
control panel, add or remove programs, Microsoft
Antispyware, change, update

 

[Mikolaj]

When I click RUN SCAN NOW nothing happens, no matter which

options are selected. The background goes blank. Task
Manager shows that the program is running, but even after
several hours last scan run area says that I have not run a
scan yet.

And start the sysem in the Safe mode and check whether MSAS works OK in this
mode - there are a few malware that block some or all MSAS funcitionality.
And the Safe mode is the easiest way to detect and get rid of them. Also you
can try other cleaning software:

Spybot Search&Destroy http://www.majorgeeks.com/download2471.html
HijackThis http://www.majorgeeks.com/download3155.html
CWShredder http://www.majorgeeks.com/download3019.html
Ad-Aware SE Personal http://www.lavasoft.com/software/adaware/
McAfee Stinger http://vil.nai.com/vil/stinger/