No boot & blue screen srror in win7 bootloade

hi all..i have a compaq presario v3000 laptop with mother board of pavillion dv2000.i had previously installed Windows Vista and by mistake installed windows 7 grub bootloader. Now my system does not start up and shows a blue screen error and shhuts down. I am not able to start the system for once. my cd/dvd drive is not in working condition.please suggest any other method to install windows freshly.or could i install windows with a pendrive?please help