Windows.MicroSoftSecurity.TaskManager fake alert

Windows 2000 Pro SP4 business machine
Becoming frustrated

I am experiencing System Tray "Your computer is infected with SpyWare.... Click here..." & "Slow operation speed may be due to spyware..." balloon alerts; unfamiliar "Windows Security Center System Warning" spyware alert windows that link to "Spy Away" & "Perfect Clean" software; and bogus "Windows Security Center" TrojanDownloader.xs alert window with "To remove dtected treat click here" hyperlink.

I assume malware has disabled NAV2003 and TaskManager, especially "Windows.MicroSoftSecurity.TaskManager" program.

Found no foreign programs listed in "Add/Remove Programs". AdAware SE was ineffective.

Spybot S&D 1.5.2 found at most 36 programs with Tea Timer running. Fixed, restart and rerun Spybot S&D 2 additional times and now finds 16 threats.

Attached is HJT log run post Spybot S&D fix.

I would appreciate any help I can get.

Thanks-LRB