So I have found out that if you install windows on an SSD and also have a HDD plugged in it will also write a tiny bit of something to that, enough to it that it won't turn on without that second one plugged in. Well i got a round that problem a while ago but now i have a bigger one.
My friend used my pc to install win7 Ultimate on his laptops SSD through one of my my sata ports. MY SSD with win7 home premium and HDD with other files were still plugged in and now it thinks that my friends SSD is the host for the os (his win7 ultimate) but it's actually on my SSD (win7 home) and it won't load it from boot UNLESS i go into bios and click on it through boot menu.
I Also can't change boot order for some reason as it only shows my HDD and ODD for boot order options.
I ALSO tried 'repairing' the pc with the installation disk but it came up with an error saying approx "you need to use the correct CD for this system) which basically means it wants the win7ult disk because it thinks that that's my OS but i what i REALLY need it to do is repair win7home on my actual SSD.
I hope you've managed to make sense out of this and have something to help me through this mess haha, Cheers.