If you still have that 240 put it back in your PC.
Well, i press "Start Windows normally" and it loads but then it randomly says "No Signal"
When you get to this message use your arrow keys to arrow up to Safe Mode near the top of your monitor. Press "Enter".
After you are in safe mode remove the AMD/ATI video drivers and reatart your PC.
If it loads to XP desk top install nVida driver from GPU CD and test to make sure your PC worked as it did before installing the 5770.
If it does then you probably have a defective 5770 that you can RMA if bought new.