I'm a new user of Ubuntu so please be gentle and patient. I hope I'm putting this in the correct place as this is my first forum entry. I have searched the forum and found several other dual boot problem threads but none seem to match mine exactly.
I have a fairly recent Acer desktop that was running MS XP pro. After MS desupported XP I decided to install Ubuntu 12.04.4 LTS in a dual boot format to do most of my computing, especially internet work, but I wanted to keep XP for offline applications that I use frequently.
When I installed XP on this machine, I intentionally left a 30GB partition of unused free space for future file storage or dual booting purposes (the machine has a 1TB HD). So, I figured I could install Ubuntu in that partition without repartitioning or messing with my XP OS or filesystem.
I installed Ubuntu and it works fine. I'm very happy with it so far and it seems to have no apparent problems. In fact I can still access my XP personal files (also in their own partition separate from the MS OS) using a "new volume" that showed up automatically in Ubuntu.
When I boot the computer Ubuntu shows as the first boot device and "Windows operating system" shows up as the last one (I also have a DOS partition that shows in the middle along with hardware boot options.
If during boot I select the Windows Operating System, XP does not come up. Instead I get a black screen with a blinking cursor in the first position. I ran the Ubuntu boot repair facility but it did not change the behavior.
I know this is a boot sector problem but I don't know why or how it happened since I installed in a separate partition and did not mess with the partitioning (or anything else) that was already on the machine.
Any suggestions would be greatly appreciated, but keep them simple please or step by step. Thank you