I recently removed Ubuntu 10.04 from my laptop for a few reasons (limited battery life, must-have apps not existing, such as Windows Live Writer that I’m using to write this post, and generally no reason to use it instead of Windows 7). In any case, my first step was to kill the Linux partition in windows from the Disk Management console, however upon restarting, Grub (a common Linux boot loader) didn’t appreciate that I had messed around with my bootable partitions, and refused to allow me to get into Windows. After a little hunting around, the solution is pretty simple (assuming you have a Windows 7 bootable DVD nearby):
1) Boot from the DVD, select your language, and get to the second screen, where you’re going to select “repair computer” (or repair my/your computer – I can’t exactly remember the wording).
2) Navigate to the command prompt and use the following commands in sequence (pressing the enter key after each command).
a) bootrec /fixmbr
b) bootrec /FixBoot
3) Reboot your machine
This information is paraphrased – I found the solution at the Neowin forums, originally posted by +Snowl. Useful information to be sure, if you randomly install linux every few months.