If you hold the Alt key until the boot manager screen shows up what's in there? Or doesn't it appear at all?
You could try resetting PRAM
Hello 88 and thank you for your response and suggestion.
When I hold the Alt key nothing appears at all. The screen remains grey and then proceeds to boot windows 7.
I tried your suggestion of resetting Parameter RAM but it didn't even work!!! I tried pushing and holding the command key, the option key, the letter P, and the letter R in 3 different ways on start up.
1) before I even pushed the computer's power button to turn it on.
2) Immediately after pushing the computer's power button to turn it on (before the grey screen).
3) Immediately when the grey screen appeared.
It's my understanding that if the PRAM is correctly reset the Mac will restart on its own. This didn't happen. On all three occasions The screen remained grey and proceeded to boot windows 7.
Try startup with some of the Apple key combos. Hold these keys on start up till something happens.
Command X to boot to OS X
Command S to boot to single user mode
Shift to boot in safe mode (be patient as it has to run a file check)
Also find the Boot Camp control panel in Windows and set the Mac to boot.
Hello dalstott and thank you for your response and suggestions.
The two shortcut keys don't work for me. When attempting them I get the grey screen and then the black screen that boots windows.
I did see on other forums about using Boot Camp control panel in Windows but on my PC I can't find it anywhere.