Anytime I start the Simple user interface the splash screen indicated a memory scan taking place, then gives a message:
“The scan completed with error. 126 = The specified module could not be found”.
clweb is right, try copying the file to the windows\system32 folder. Interesting that Dreamweaver uses psapi.dll, but unless you have the Dreamweaver folder on the PATH, avast cannot access it. Placing it to the system directory will let avast use it (alternatively, you can copy it to the avast4 folder).
Please send us the result of this test – I’m quite curious. I’ve seen more people having the same problem on NT4.