I'm using a WD 500gb notebook drive in my laptop and now it keeps restarting so I tried reloading windows and it got stuck but when I install a new hdd its works fine also when I use the 500gb as external it seems to be working fine.
Any ideas why this is happening?
Sounds like the HD has some bad sectors. Loading the OS uses a lot more of the drive than using it as an external drive and copying a file or to to it. Did you run any error checking program to do a surface scan?