If Windows stops responding (hanging) or reboots randomly for no apparent reason, then the problem often lies in defective memory. If you have overclocked your computer's processor or set the memory timing manually, try reverting back to defaults - this might help more than you can imagine.
To set your computer to start from CD or USB, read the Computer boot order article.
Memtest86+ should be run before trying to boot Data Recovery CD. This will make sure that the Windows Preinstallation Environment works correctly.
After your computer starts from www.winhelp.us Data Recovery CD, press Enter or Space on keyboard within 5 seconds to open Data Recovery CD menu.
Bootable Data Recovery USB disk users do not see this dialog.
Use arrow keys to select Memtest86+ in the menu. Press Enter to run the program.
Please note that bootable USB disk users see a bit different dialog.
Memtest86+ offers Fail-Safe Mode for a few seconds before starting the memory test. If your PC has stopped responding or rebooted by itself during previous tests, press F1 key.
Normally, you do not need the Fail-Safe Mode.
Let Memtest86+ run for 15-20 minutes before checking any results. Although Memtest86+ will easily run for hours, the first 15-20 minutes will always confirm the state of your memory modules.
If a memory module is not working correctly, Memtest86+ might stop responding or reboot computer. Check that WallTime value is increasing every second and use Fail-Safe Mode the next time.
If after 15-20 minutes values in last two columns, Errors and ECC Errs are 0 or empty, the memory in your computer is fine. ECC Errs will be displayed only if your computer and memory module(s) support ECC (Error-Correcting Code).
If an error count is over 0, you must replace the defective memory module(s). As said before, defective memory will lead to unexpected errors, random reboots and data loss.
Here is a computer with good memory modules.
To exit Memtest86+, press Esc key on your keyboard. Your computer will reboot. Remove the CD, USB or floppy disk and let Windows start normally.
Because there are very many different memory module types (such as SDRAM, DDR, DDR2, DDR3, etc) and they also have different working speeds, I recommend reading the Memory and hard disks article to determine which memory module(s) your computer needs and whether there are available memory slots. The point is that you cannot put just any memory module in your computer. A possible solution is in the manuals that came with your computer - supported memory types and speeds are listed there.
If you have overclocked your computer, try changing settings back to defaults first. Memory modules might not be able to run at higher speeds or voltages.
Then run Memtest86+ again.
If your computer is still under warranty, check the manuals that came with your computer to find out where to call or where to take your computer.
If you do not know much about computers and parts they consist of, I strongly recommend having memory modules replaced by a specialist. Otherwise you might end up with broken memory modules, electronic parts ruined by static electricity, unintentionally unplugged cables or some other malfunction.