This error has been known to occur as a result of one of the following causes: Cause 1: BOOTMGR is compressedįile compression is a feature that allows the user to decrease size of files, folders, and programs, and reduce the amount of space they use on the hard drives. It’s been noted to present as any of the following: Press Ctrl+Alt+Del to restart Other Known Variantsĭue to a bug in Microsoft’s filesystem compression code, the filename that presents can be something else. However, if the bootsector detects that the BOOTMGR file is compressed using built-in Windows file compression, then the boot process halts and the “BOOTMGR is compressed” error screen appears. This file is usually located in the root directory of the active partition on the first boot drive.

On newer systems, this bootsector code is tasked with loading the BOOTMGR file, which is used to load the operating system kernel and start up Windows. That MBR code in turn loads the bootsector from the active partition. When a computer is turned on, the BIOS picks an eligible, bootable hard drive and then calls code stored in the MBR at the start of that hard drive. Symptom 1: “Bootmgr is compressed” error screen on startup The error messages, alerts, warnings, and symptoms below are tied to this error. The following information on this error has been compiled by NeoSmart Technologies, based on the information gathered and reported by our global network of engineers, developers, and technicians or partner organizations.

Windows 7 bootmgr is missing fix