Merging problem

I realize this will probably result in a torrent of abuse and eye rolling but for the more patient helpful people, here's my problem....

I currently have two 'Macintosh HD's on my desktop. They both have 10.4.10 installed on them separately and have been recently restored, so I have no desire to keep any files on either partition. All I want to do is make them one again, 'merge' them together, I'm happy to loose any information, I just can't seem to merge them in Disk Utility.

Any support would be great! Thanks

I would suggest you use original OS X dvd and reinstall from scratch. You should be able to revert back to one partition in the install process.

when I reinstall from the original install DVD it asks me which drive would I like to install OS X on and gives me and an option of the two 'Macintosh HD's there's no option to merge

Back-up any files you want to keep first

when the install screen comes up, go to the menu and select disk utility from the menu.

Reformat the drive as one partition then proceed with a clean install