General :: Lost Grub - Can't Boot Ubuntu 9.10 ?

Today I was forced to reformat windoze and of course lost grub so I can't boot ubuntu 9.10. I found two suggestions in previous posts which didn't work. One suggested using the install disk as a rescue disk and as root run grub. I entered sudo grub and the cmd was accepted but the cmnd grub was not found.

The second was to sudo grub -install and again grub was not found. Both these suggestions were for a win 98/mandrake installation.

Do I have to reinstall ubuntu? If so there is a problem in partitioning. Setup sees there is already an ubuntu os on the disk. In fact two of them. I forget why, but I reinstalled ubuntu and ended up with two in the grub menu. I was advised not to try to repair grub and didn't. Now I have two and it thinks I want to put the third one side by side, or erase and use the entire disk. There was a third choice but I forgot already exactly what it was and didn't like it anyway. If I erase and use the entire disk, won't I lose windoze? If I put them side by side I will then have three which which will waste disc space. The discs aren't that big being only about 10gb. I don't think I want to waste the space with a third ubuntu.