That's right.
Sometimes it'll work if you install proggies twice in the same folder, first from one OS and another time from other OS.
Some programs which doesn't make changes to registry may work without even doing that, just locate the EXE and try if proggie works.
btw if I was you I'd clean one of those 25gb partitions and the I would install XP on that one and format it to NTFS when installing.
Another way would be split that 10gb partition to two with "Partition Magic" (maybe make it larger with same proggie by taking space from those two other partitions).