The following hardware adapters will help you to access and recover files from a hard drive when your computer fails to start.
2.5 to 3.5 adapter for IDE hard drives

With this adapter you can connect a 2.5″ IDE laptop hard drive to a desktop computer.
Here’s how it works.
1. Plug a 2.5″ IDE laptop hard drive into one side of the adapter which has two rows of holes.
2. Connect the other side of the adapter (with two rows of pins) to a regular 3.5″ cable in your desktop.
Most likely both cables in your desktop are already connected to other devices (hard drive and optical drive). You can temporarily unplug the cable from the optical drive and use it for the adapter. When you are done, connect the cable back to the optical drive.
3. You plug the white connector into the available power connector in your desktop.
That’s it! Now you can start the destkop and your laptop hard drive should pop up in My Computer as a regular drive. Now you can access the drive and back up personal files.
This adapter will work with all 2.5″ IDE laptop hard drives. Search for a cheap 2.5″ IDE adapter here.
Hard drive adapters come in many different shapes and on the picture below you can see a different adapter. Even though it looks different, you connect it to a desktop computer the same way as the first one.

If you are trying to access an IDE hard drive, make sure your adapter is made for IDE (not SATA) hard drives.
2.5 to 3.5 adapter for SATA hard drives
This adapter for 2.5″ SATA laptop hard drives might look similar to the previous one but if you take a closer look at the connector you’ll see it is shaped differently. Instead of two rows of holes it has two flat connectors. This adapter will work only with SATA hard drives, you cannot use it with IDE hard drives.

This adapter will work with all 2.5″ SATA hard drives.
By the way, if your desktop supports SATA hard drives you can connect your 2.5″ SATA laptop hard drive directly to the motherboard using regular SATA cables. Search for a cheap 2.5″ SATA adapter here.
USB adapter for laptop and desktop hard drives
Another fast and conviniet way to connect your 2.5″ (laptop) and 3.5″ (desktop) hard drive to another working computer is using a USB adapter. All you have to do is connect the hard drive to the adapter and plug the adapter into the available USB port on a working computer.
On the picture below you see an adapter designed for IDE hard drives.

There are many different universal USB adapters designed to work with most 2.5″/3.5″ IDE/SATA hard drives. One of these adapters you ca see on the picture below.
After the adapter is connected, the computer will detect new hardware and install the driver. The hard drive will pop up in My Computers. Search for cheap USB adapters here.