Zitat von http://h30434.www3.hp.com/t5/Notebook-Boot-and-Lockup/Pavilion-g7-Hangs-at-Windows-Logo-Screen/td-p/2835745
After hours researching did give up.. so what I did?
1.Did replace a hard drive.. New one.. Unformatted…
Same problem… computer freezes.. Takes longggggg time to do something..
2.Did connect the original hard drive to my desktop using usb adapter… did read it… no problem.. works good.
3.So Hard Drive is not the problem..
NEXT >>> Unplug Battery. Unplug New Hard Drive. Take out memory...
THEN >>> ('yes i'm a programmer)
Step 1. Power up…
Result: beeps for memory
Step 2. Insert one memory…
Result: It Works… Startup OK. Good.
Step 3. Connect Hard Drive
Result: It Works… Startup OK. Good.
Step 4. Insert the other memory
Result: It Works… Startup OK. Good.
Step 5. Attach the Battery…
Result: COMPUTER FREZEES AT STARTUP… LONG TIME TO DO ANYTHING… …BAD.
IT WAS THE BATTERY… All the time it was the battery..
Took battery out.. Restart … Result: It Works… Startup OK. GOOD.
Now I just need a new battery..
Sometimes is just the power button… 
Hope works for you guys….