Can't get Standby, other programs to run

As of about a month ago, whether a batch file program auto-runs or by pressing the Windows key, Standby mode doesn’t work. It may be linked to recent MS updates and the problem seems to occur after the CIS anti-virus program runs. There was no problem before the updates. I also noticed that after the antivirus program has run (and there are no error reports), that other programs don’t run, including Task Manager. Instead, the following is displayed when I try to open them:

“This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix the problem.”

Everything seems to run fine after I either shutdown or restart the system, including Standby. I’ve run System Restore to the pre-Windows /CIS software update installation, and the system worked ok. But the updates were reinstalled again.

My system description:

HP Pavilion 750N, Pentium 4 CPU 1.60 Ghz
MS Windows XP Home Edition
Service Pack 3, SMBios version 2.3
786 MB RAM
40 g HD
Airlink101 Wireless Monitor adapter
Fios Internet
Internet Explorer 8
Firefox 7.01
Comodo Internet Security Premium 5.8.21334…

Your help is appreciated.