i got a virus on my laptop that i couldn't shift so i tried reinstalling windows 7 but i didn't have enough space so i deleted some files still didn't have enough space. So one of the options when installing windows 7 was to format my laptop so i clicked format and it just shut down and now keeps coming up with bootmgr missing any ideas how to fix this. I've tried installing windows again but says file is corrupt..oh it also says i have no OS installed

Bootmgr is missing is the common reasons for windows won't start. There are few ways that the "BOOTMGR is missing" error may show up on your computer, with the first error I have listed being the most common:
* "BOOTMGR is missing Press Ctrl Alt Del to restart"
* "BOOTMGR is missing Press any key to restart"
* "Couldn't find BOOTMGR"

The "BOOTMGR is missing" error displays shortly after the computer is turned on, immediately after the Power On Self Test (POST) is complete. Windows has only initially started to load when the BOOTMGR error message appears.

Reasons of BOOTMGR Is missing Errors
There are a number of possible causes for BOOTMGR errors, including the most common "BOOTMGR is missing" error message.The most common reasons for BOOTMGR errors include corrupt and misconfigured files, hard drive and operating system upgrade issues, corrupt hard drive sectors, an outdated BIOS, and damaged or loose hard drive interface cables.
Another reason you might see BOOTMGR errors is if your PC is trying to boot from a hard drive or flash drive that is not properly configured to be booted from. In other words, it's trying to boot from a non-bootable source. This also would apply to media on an optical drive or floppy drive that you're trying to boot from.

How to Fix Bootmgr Missing Error
To fix bootmgr error, I recommend Tenorshare Fix Genius. Fix Genius allows you to boot up any computer with a bootable CD/DVD/USB to fix computer booting issues. Not only this software can fix bootmgr missing error, but also can apply on ntldr is missing error.

How to Fix "BOOTMGR is missing" Using Tenorshare Fix Genius.
Step 1: Burn a Start-up CD
Download, install and launch Fix Genius on a usable computer. Insert a CD into this computer. Here you can use a DVD disc or a USB flash drive as an alternative. This software will automatically check your CD drive, and you just need to click "Burn" button only to finish the process of burning a boot CD.
Step 2: Boot Your Computer from CD
Since you can't login into Windows system from hard drive normally, you need to utilize the CD you burn in Step 1. Plug it into the computer that appears errors. Change the boot order in BIOS setup to set the CD as the first boot device. Your computer will reboot automatically and enter the system which is burned on the CD.
Step 3: Fix "BOOTMGR is missing"

After you load into the system, you will see a desktop. Double click the icon of Fix Genius to launch it.This Windows 7 Recovery disk offers 3 crash solutions Go to "Windows Rescue" and select "Crash before Loading Bar". Because the causes of such an error are varying and complicated, you need to try the tools this software provided one by one until your computer works well.