(solved)help with choosing os to startup

I originally had win 7 installed on my c drive. I then installed win 8.1 on the d drive. now when I boot my computer only windows 8 runs and I notice that it changed to the c drive. how do I change it back so that win 7 is my c drive? thanks in advance
Answer #1
Its usually F11 while your computer is starting up to the motherboard BIOS settings from there you change boot order, and hopefully the two drives have just changed letters (for some reason, wouldn’t have a clue on that one). If you still have the two separate/partitioned drives and change the original boot up from one to the other I bet windows 7 will load.
Answer #2
thanks . i ended up just putting my win 7 disc in and doing a startup repair and it fixed it..
Answer #3
No prob, but I would of rather-ed be helpful and you use my idea!!
Answer #4
OK, so you’ve fixed it but you could have typed msconfig in the RUN command, clicked the boot tab and changed it that way.