bootmgr is compressed in windows 7 and also I am not able to change the boot priority

Hi all,

I have dell inspiron with windows 7 installed in it. My younger brother did compressed some files. After that I am getting this bootmgr is compressed- press ctrl+alt+del to restart error.

I googled it and found a lot of solutions to try.

Some of them is to run the system startup repair using windows DVD or usb flash drive.

Now problem is I am not able to boot from DVD as well , because I guess My boot priority is set to HDD.

I wanted to change the boot priority, but I am not able to get that option also. I tried pressing every possible key from F1-F12, Del and even CTRL buttons. But none could take me to boot priority setting option.

I even removed my battery and tried connecting my laptop to power directly that too could not help to reset BIOS setup option as , I read somewhere that this could lead the motherboard to do the hardware reset and bios reset.

Please help me with this.

Thanks in advance,
Jitesh