I recently replaced the hard drive from a gateway laptop into a HP laptop. The hp is missing the wireless adapters and I am going to download the drivers. My question is do I download drivers based on the gateway hard drive or the HP laptop?
You need the drivers for the HP laptop - that's the piece of equipment that is in current use. You're very lucky you got away with swapping the hard disk over - has the operating system validated with Microsoft? Usually, a system from one manufacturer will not migrate to another and I'm surprised you only need one driver.
Find the wireless adapter under Network Adapter in Device Manager then right click it and go to Properties and then click the Details tab. Scroll to HardwareIDs and take a note of the four characters which follow VEN for Vendor and also the four following DEV for Device.
Go to http://www.pcidatabase.com and input those characters in the two relevant boxes and follow the trail to the right driver. When you find the list of the Vendor's drivers, they aren't in order so use your browser's Find facility to track the Device details. With luck you'll have an executable file but some will be a zipped folder.