Gateway GT5657E hard drive

i'm not too sure what you mean but here's the manual telling you how to add or replace a hard drive http://support.gateway.com/s/Manuals/Desktops/8512418.pdf
it could be better for you to purchase a portable hard drive. External Hard Drives Newegg com

This model Gateway is installed with a
250 GB 7200 RPM Serial ATA hard drive
You can install any make of SATA hard drive you wish, you may like to install a larger capacity SATA hard drive.
These SATA hard drives can be purchased over the Internet or at any computer shop.

How to Remove Replace and Install Your Gateway MX series MX6428 Laptop Hard Drive

1. On the bottom of your Gateway MX6428 laptop, find the hard drive door to access the hard drive.
2. Remove the Screws.
3. In this step, you will either need to pry out your Gateway MX6428 hard drive caddy, or simply remove the door.
4. Once the Gateway MX6428 hard drive is removed the laptop, you need to remove the hard drive caddy. There are usually four screws to remove from the caddy.
5. Simply Insert the new hard drive into the caddy. Place the screws back in. Install your new Gateway MX6428 hard drive.

The Gateway M465-e is only compatible the SATA hard disk drives. If the drive you are using is not a SATA drive, then it will not be able to work with your hard drive.

the BIOS needs to recognize the new drive. Check with gateway web site under support for note on upgrading the HD.

Immediately back up your drive contents to an external USB hard drive or other device. Buy a new hard drive, install it according to the instructions. Many drive manufacturers include software and directions to copy the complete contents of the old drive to the new drive. Hopefully, you'll be able to get this accomplished before it all comes tumbling down. The fewer times you shut it down and restart it, the better. If the information on the drive is critical, get something like Acronis drive imaging software to "snap" an image of the drive and put it on an external drive. If you haven't burned the restore disks, follow the manufacturer's directions so that, at worst case, you can get it back to factory new condition, which will leave you without your files.

in most new cases there are extra slots for extra hard drives, but as long as the ide or sata is hooked up it should work, and you can buy hardware and rig up something ,ive tested many hard drives without hooking up hardware,
the components on the hard drive should not touch other metal

You may need to try installing windows xp. I had a gateway that had a brand new hard drive and wouldn't take 98, but installed xp flawlessly. Look at the computer and see if it says designed for Windows XP

Hard drives do not come with OP's ready installed. There will be no information on it. You will have to install something like Windows XP/Vista. To do this you need the installation disc. Without it your computer will not be able to operate.

sounds more like a power supply issue as these are both powered directly by the power supply. check your power cables inside the case and make sure you didnt bump them or leave them disconnected when you installed the harddrive.