The dreaded message “bootmgr is compressed” is another bugger and requires some work on your side.
I happen to run into a lot of errors in Windows 7 due to file compression. I’m not saying that it’s bugged, I’m just saying that it’s causing problems for my own setup and is even slowing it down.
Anyway, if you run into this error, your bootmgr file is probably located on another drive than your Windows 7 main partition. Thus, you are receiving the error. The bootmgr file will be written to the BIOS default HDD, but if it’s on another hard drive then it can get compressed.
So, what can we do about the error “bootmgr is compressed”?
Repair your computer
Press F8 during boot up to get a list of all start-up options. Choose “Repair your computer”:
A list of your installed OS’s will appear:
Method 1: Repair bootmgr via Command Prompt
Open the command prompt.
Next, simply enter the following command to fix your boot record:
In case your master boot record has been damaged as well, I would also run
If that doesn’t solve the problem, you can also try to run the following commands to re-create your bootmgr file. You are basically creating a temporary bootmgr file and then replacing it with the original one:
Each command has to be on a separate line:
expand bootmgr temp
attrib bootmgr -s -r -h
ren temp bootmgr
attrib bootmgr -a +s +r +h
I would also recommend to uncheck the option “compress to save disk space” for each hard drive and partition. Mainly, because it can cause problems like this one and it is slowing down your PC eventually.
Method 2: Repair bootmgr via “Startup Repair”
Theoretically, Windows 7 should be able to find and fix this error. If you click on “Startup Repair” instead of Command Prompt, then Windows will scan your system for common errors and will hopefully figure out that your bootmgr is broken.
Check disk for errors
Another error why you are receiving the “bootmgr is missing” error after installing Windows 7, might be that your hard drive has disk errors. It is always a good idea to also run the command
chkdsk C:\ /f /r
This might take some time, depending on the size of your hard drive, but it is necessary to verify that there are no corrupted files on your disk.