Boot Manager is compressed
If by accident having compressed the entire boot partition, then Vista will display the following error:
BOOTMGR is compressed. Press Ctrl+Alt+Del to restart
Check points for fixing compressed boot-manager: •Boot into Windows Recovery Environment (WinRE) and perform a "Startup Repair".
•If the above doesn't solve the problem then boot into WinRE again, but when selecting the Vista-installation, then press "Load Drivers" (Instead of "Next") and use the mini Windows Explorer to right-click the boot-drive and deselect "Compress this Drive" and choose Apply to sub-folders and files.
•If that also fails then boot into WinRE again, and go to the "Command Prompt" and execute these commands: ◦compact /U C:\bootmgr
◦compact /U C:\ntldr
•If you for some strange reason have lost your Vista DVD, then you can also use a Windows 2000 / XP install CD and enter the recovery console instead and execute the following commands: ◦attrib -c c:\bootmgr
◦attrib -c c:\ntldr