Help, Monitor problem

Ok this is gonna start of weird so just bear with me here, i have a xbox 360 but i got the red ring of death, so my 19 in westing house monitor wasn't goning to be used for 5 weeks untill it is repaired so i thought i would hook it up to my laptop, which by the way is running mac osx 10.4.8 and windows xp, it a hackintosh as somesay but anyways it was working fine i had a bigger mac screen and windows screen, i was playing Rome Total war i was done and wanted to get back to mac, and cause im lazy and windows is slow i do as some say a hard boot, and hold the power button till it turns off. But now when i start back up mac or windows it sees the monitor and lets me change options about it but the monitor just says no input display, and just to see if it still worked i tried my xbox 360 on it and it worked fine, well before the 360 crashes. And when i boot into windows it sees the monitor but thinks the plug and play monitor is default and my laptop screen is the monitor it's like they got switched, even though i have the windows bar onthe bottom still when it was suppost to be on the other monitor. It's really weird but i jsut wan't some insight on what i should do it's now an emargency cause the normal screen still works but i would just like the bigger screen back, well dual screens. So basicly the monitor is there and connected both oses reconginize it but no image shows. Thanks in advance.