Having been in the IT game for over 10 years, I don’t see much that is genuinely a new one on me but I did this weekend. As a favor to a client I took in a PC which belonged to their parents. It was working fine and then it wasn’t is basically the scenario as described to me. So I plugged it in and booted it up only to be presented with the blackscreen and white text of doom but instead of saying ntldr is missing which I have seen numerous times, it reported:

“BootMGR is compressed”

Windows obviously needs the BootMGR to be uncompressed to initialise the booting process and so I started to look for solutions and a couple soon presented themselves:

Option 1: Rebuild the BootMgr using Windows Vista/Windows 7 Install CD

insert your OS CD
go to DOS window and type in your OS driver (usualy C:/
type in bootrec /FixMbr
then type in bootrec /fixboot
then type in bootrec /rebuildbcd
then type in exit
restart your coputer

Could I find a Vista Home Premium to do this from? No, I couldn’t which is both annoying but also shows how rarely we deal with Vista PCs – people are learning that Windows 7 is well worth the upgrade.

Option 2: Roxio BootMGRfix *Be warned – read fully below*

Reading around on some HP forums, I found reference to Roxio (those of the CD burning software fame) and a small tool they have available called Roxio Bootmgrfix which is designed for this very problem. Its essentially a bootable pen drive which will decompress the Bootmgr automatically. You can get the software by registering with Roxio here: http://www.roxio.com/go/bootmgrfix

I downloaded the software and used it to prepare 2 memory sticks, each of which it detected, formatted and attempted to copy the required files over, but both failed and left the memory stick unreadable – I think  they are recoverable but haven’t had time to fix them yet. Needless to say I gave up on this idea after 2 sticks and went for the next option.

Option 3: Decompress the C: drive through a bootable recovery CD

I should really have thought of this first, and as always the simplest things are the best. I suspected that the Bootmgr became compressed through Windows compressing the C: drive to save space. I booted into Windows PE recovery disk (there are many available) and used the windows explorer to right click on the C: drive, chose properties and sure enough there was a tick in the “Compress this drive to save space” option. I deflagged this and let Windows do its thing. After a few “This requires administrator permissions” UAC boxes and a few clicks of the skip button and about 5 minutes, the process was done. A quick reboot and hey presto – all is well again.

Another fun weekend had by me! I hope this article helps someone out.