Remove entries from System Configuration Utility (MSCONFIG)

Problem
When using Microsoft's System Configuration Utility (MSCONFIG), unchecking a startup item does not remove it from the listing.


Fix
When you uncheck an entry in the System Configuration Utility, a sub key  is created in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\MSConfig\startupreg for that particular entry you unchecked. Delete the subkey from the previously mentioned registry key.


Example
In System Configuration Utility, I had an entry for "Reader_sl". This entry pointed to C:\Program Files\Adobe\Reader 9.0\Reader\Reader_sl.exe". I removed the checkmark next to "Reader_sl". Now the item no longer runs at startup. However, "Reader_sl" is still listed in the System Configuration Utility (but it doesn't have a checkmark beside it).

In the registry, I deleted HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\MSConfig\startupreg\Adobe Reader Speed Launcher. The entry for "Reader_sl" is now deleted from the listing in System Configuration Utility.

The usual warnings of "registry editing can cause major damage to your system, etc", "be certain to back up your data, etc" apply.