Why would you need to diagnose memory in your laptop? Let’s say you have one of the following problems:
1. Laptop starts intermittently. Sometimes it works just fine, sometimes it fails to start at all.
2. Laptop starts normally, then displays a blue screen error (BSOD) and restarts.
3. Laptop freezes.

All these problem can be related to the memory failure and you can test it with a great free diagnostics tool Memtest86+.

Here’s how you can create the diagnostic CD and run it on your laptop in a few relatively easy steps:

Step 1.
Go to the Memtest86+ download page and grab the latest version. If you want to run this utility from a CD then you are looking for an ISO image. Download the ISO image and unzip somewhere on your desktop or any other location.

It is possible to run this utility from a floppy disc but most modern laptops are sold without floppy drive. You can run it from an external USB floppy drive. In this case you’ll have to download package or floppy.

Step 2.
You can burn the ISO image on a CD disc with most CD burning software. If you don’t have CD burning software installed on your computer, you can use CDBurnerXP – a free CD and DVD burning software. You can grab this software here. Download and install it on your computer.

After CDBurnerXP is installed, go to File and select Burn disc from ISO file…

Click on Select ISO image to burn and navigate to the location where you saved the Memtest86+ ISO file. After that click on Burn disc and wait until your CD is completed.

Step 3.
Now, after the diagnostics CD had been created, you can run memory test on your laptop. In order to run this test, you’ll have to boot the laptop from the diagnostics CD.
You can enter the boot menu and choose to boot from the CD. Alternatively, you can enter the BIOS setup menu, set the CD/DVD drive as the first bootable device, safe settings and restart the laptop. Now it should start booting from the CD.

The memory test will start automatically. All you have to do is wait until it finishes at least one pass. I would recommend running it through more then one pass.

If the memory passes test, you’ll see Pass complete, no errors message.
If the memory fails test, you’ll see a lot of red lines with errors. If you see errors, apparently it’s time to replace RAM.