So, you had Linux running perfectly in a dual boot with Windows, but then Windows became “junked-up” and you needed to reinstall. You went through the agony of spending nearly an hour with the Windows setup and then many more hours installing drivers and software. Everything in Windows was now working appropriately so you decided to boot back into your Linux flavour of choice only to find that you could not boot it! Why? Windows took over the master boot record (MBR).
Allow me first to qualify why some Linux users still use Windows occasionally. Some games still do not run well in Linux even with the development of Wine and Cedega. For me, Battlefield 2 installed and ran using Wine; however, online play was not working properly because of the need to use PunkBuster. For this reason I must have a Windows installation on my PC.
When installing Linux after Windows, both GRUB and LILO boot loaders recognize that Windows exists and offers a menu during startup to select the operating system you wish to boot. Windows, on the other hand, believes it is the only operating system around and does not recognize a Linux installation exists and therefore does not offer a menu during the system boot. When I first came across this issue many years ago I figured there was nothing I could do about it and ever since have been installing Windows followed by Linux (however, I often feel my Linux installs do not require being reinstalled).
The current Windows XP install on my machine was once again slowing down, possibly due to driver conflicts, but the reason is neither here nor there. I simply wanted to reinstall Windows as many Linux users would like to. I decided this time to find a solution so I would not have to ruin my near-perfect installation of Ubuntu. Venturing to the Ubuntu forums, I quickly found a thread offering a tutorial on accessing the Ubuntu installation. Basically, the issued is resolved by restoring GRUB (or LILO) and then pointing GRUB (or LILO) to both the Linux and Windows partitions, thereby allowing selection of the operating system of choice during boot. You can read the thread.
Another excellent article on editing GRUB can be found on the tuxmachines.org website.
Until next time,