On startup, if the Windows system stops with an error message of 'bootmgr is compressed', the C:\ drive of the system might have been compressed. The error can be fixed once the system has been repaired. At times,when trying to create space, users might accidentally compress the hard drive.To repair the PC, the operating system installation DVD is required. Through the repair disk, the hard drives can be browsed and fixed by un-checking the compress drive to save space option. The system needs to be restarted for the modifications to fix the bootmgr is compressed error.