Boot.ini tab is missing in MSCONFIG?
When you start MSCONFIG.EXE (System Configuration utility), the BOOT.INI tab which usually appears, may be missing.
This may simply be a file permissions issue. You can verify that by typing C:\Boot.ini in Start, Run dialog. If you get Access Denied or similar error, that explains the problem.
Here is another obscure possibility:
Open Regedit and navigate to:
Backup the key by exporting it to a REG file
In the right-pane, delete the value named Boot.ini (if found)
Close Registry Editor and open MSCONFIG.