Failed to instantiate file "TopAnswer.webpart" from module

Error:

Failed to instantiate file "TopAnswer.webpart" from module "WebPartPopulation": Source path "dwp\TopAnswer.webpart" not found. Troubleshoot issues with Windows SharePoint Services.

Solution:

This error will occur, if you applied only the WSS 3.0 SP2. You may not installed Office Server SP2.

I wrote a simple solution in another post. Just go through the url and install Office Server SP2.

http://sensoft2000-sharepoint.blogspot.com/2009/07/moss-2007-database-attach-error.html