Event ID:1015

Error: 0x800401f0

Got one of these on a server when attempting to install the .net FrameWork 2.0 and Sharepoint Services Service Pack 2 on a Windows Server 2003 SP1 machine. 

The fix is to follow http://support.microsoft.com/default.aspx?scid=kb;en-us;555175

Unregister Windows Installer, and then reregister Windows Installer. To do this, follow these steps:
 
1. On the "Start" menu, click "Run:.
 
2. In the "Open" box, type "msiexec /unreg", and then press ENTER.
 
3. On the "Start" menu, click "Run".
 
4. In the "Open" box, type "msiexec /regserver", and then press ENTER.