Right,where to start? I've been modding my XP powered PC and everything has been going fine,until yesterday,I fitted my Corsair H50 liquid cooling kit,everything fitted fine

So far so good.
Used the PC all that evening and it was running like a dream,switched it off,went to start it up the next morning and now all I get is lockups,nothing but

Reboot it and it wll run for 5-10 mins,very slowly,until it just locks up entirely,forcing a reboot

Nothing has changed software wise,and every thing hardware wise has been checked and double checked and its all good,so whats gone wrong?
Even starting in safe mode doesn't last for long,you think you've got it stable again and then it just hangs

Its just driving me nuts as to what it can be,any suggestions or any ideas would really help cause at this moment its looking like I'm going to have to trash the HD and start again

Thank you.