me laptop me jab win 7 instal krta hon to thek chalta ha.jab win vista krta hu to instalation mukamil hone ky bad jab 1st time start hota ha to blue eror dy k band ho jta ha.aur jab win xp krta ho to jahan setup is now starting window ata ha jis ky bad partation ati hain wahan blue eror a jta ha.win 7 belkul thk chalta ha help me.win 7 mujy nai pasand.