was your laptop plugged into the power adapter when you tried to install windows? if so, unplug the battery, use power adapter only. If not unplug battery and power cord, press and hold your power button for 15 seconds, then plug both battery and power cord in.
put your windows 7 disk in and press f12 at start up to get into the boot manager. it should give you a list of options to boot from. you want to select boot from dvd drive/cd-rom, (it might have some weird name, just make sure you DON"T select your hard drive or usb. After selecting it, you should get a different screen that prompts you with a message saying "press any key to boot from cd", just press enter and it will take you to the start up screen. when you go to install, click custom install and delete both partitions until you see just one partition. Then click create new. windows will say that it needs to create a partition for system files, click ok. you should be good to go after that.