Try the Installer Cleanup utility:
http://support.microsoft.com/default.aspx?scid=kb;en-us;290301
See if you can spot dependency.msi, although that sounds suspiciously
generic--could be a bug of some kind, rather than an installer issue.
You might also try:
Control panel, add or remove programs, microsoft antispyware, change, then
update.
(on the theory that your original install is in some way slightly defective)
When I start Antisypware, I get the following screens. I searched my
computer for Dependency.msi and it isn't here at all. If I click Cancel,
the same pair of screens repeat. Cancel, again, it repeats. Cancel a third
time and it apparently stops trying and runs AntiSpyware. It seems to work
just fine.
Any clues?