Symptom:
When you try and edit the crawl schedule in MOSS, you get an access denied:
Access is Denied (Exception from HRESULT: 0×80070005 (E_ACCESSDENIED))
Problem:
The wss_wpg doesn't have read/write permissions on the Windows/Tasks folder
http://support.microsoft.com/default.aspx?scid=kb;en-us;926959&sd=rss&spid=11373
Solution:
1. Change attributes of Tasks folder by typing this in a command prompt:
attrib -s c:\windows\tasks
2. Restart Windows Explorer.
3. Add the wss_wpg account with read/write permissions to the permissions of the folder
4. Change the attributes of the Tasks folder back to a system folder:
attrib +s c:\windows\tasks