Windows Vista/7/2008/BartPE/WinPE/WinXP Live: Method #1: 1. Boot up to installation DVD/CD. 2. Click install but don't follow through. 3. Press SHIFT-F10 to bring up console. 4. Type "diskpart" 5. Once inside diskpart type: -> list disk (find the one you want to convert) -> select disk 0 (select the one you want from the list) -> convert mbr (should take a second or two) -> quit 6. Continue with install
Method #2: 1. Boot up to installation DVD/CD. 2. Click install but don't follow through. 3. Press SHIFT-F10 to bring up console. 4. Type "diskpart" 5. Once inside diskpart type: -> list disk (find the one you want to convert) -> select disk 0 (select the one you want from the list) -> clean (wait an hour or so until its done) -> quit 6. Continue with install