There are multiple types of blue screen or blue screen of death errors in a Microsoft windows based OS. Before fixing it, it is neccessary that you should know the types.
If you get only blue screen without the error codes, probably the problem is with video card or the monitor. Check your video card and monitor in this case.
If you are getting a blue screen and then your computer suddenly reboots without being able to read the text in the blue screen, follow the steps below. when you are unable to get into Windows to perform the steps below, boot the computer into Safe Mode.
If you are unable to boot into Safe Mode, you may have corrupt Windows system files, a defective memory chip or a damaged hard drive. You should run hardware diagnostic tests to determine if the memory or hard drive is causing the blue screen errors.
**right-click on My Computer or Computer, from the start menu or desktop.
**Click the Properties option.
**In the System Properties window, click the Advanced tab.
**On the Advanced tab, go to Startup and Recovery section and click the Settings button.
**In the Startup and Recovery window, uncheck the Automatically restart check box.
Blue screen errors
Windows NT, 2000, XP, Vista, and later versions of Windows have a blue screen error that is similar to the example shown below. These error messages often contain more detailed information and will contain information that you can search and find. If you’re not getting a blue screen error that looks like the example below, refer the fatal exception error troubleshooting.
Locate the line containing all “capital letters with underscores” instead of spaces, such as the above example, BAD_POOL_HEADER. Write this information down. If you do not see anything written in all caps with underscores like this, skip this step.
Get either the STOP: error message at the top of the error, or in the “Technical Information:” portion of the error. For example, in the above error, it is STOP: 0x00000019, write the first portion of this error message down.
Finally, if technical information is shown, write down the file and the address.
Once you have the above information, you can start troubleshooting the issue.
For information on slow running computers refer this link.