A computer that hangs during start up could have problems relating to hardware and/or problems with operating system, you could take your computer to a computer repair shop but that is not always necessary. I will talk you through possible fixes you can do in your own home.
Presumably, your computer is reaching the BIOS (Basic Input Output System) systems check, or POST (Power On Self Test). This is signified by the lines of text that appear on the screen before the operating system starts. The text lines are a display of the results from the BIOS system check (POST). You should notice a listing of the various drives connected to your computer. Typically, at least one hard drive and one optical (CD/DVD) drive. There will also be an indication of the status (passed/failed) of the system memory, and a listing of the peripherals attached to, or built into, the computer’s motherboard. If any of these items fails to show up, it could mean that the particular device has died or has become disconnected.
Computer Repairs that may be Required if Hanging During Power Up
If your monitor is displaying a blinking cursor, then you need to pay attention to the “beeps” that the computer makes when you switch it on. The BIOS “beep” codes can provide a starting point for investigation. However, these codes are not standardized and vary between BIOS Providers. There is one code that is common to all providers, and that is that a single beep is an indication that the BIOS has passed POST. If you receive anything other than that, there is a strong probability you have a hardware problem.
Before rushing to the experts, there are some computer repairs that you can try at home. When the computer is turned off and the computer’s plug removed from the outlet open the computer case. Use a soft-bristled brush and your vacuum cleaner to tidy the insides. Be careful not to dislodge/disconnect wires or components during cleaning. Do not be surprised to find collected dust inside, as most people are not aware that they need to periodically clean inside the case. This is typical, and could indicate an overheating condition.
Once the cleaning has been completed, check the wire connections and ensure they are fully coupled. If your computer has additional boards attached to the mother board, then you should verify that they are in place. These boards plug into sockets located on the mother board, and can become slightly “unplugged” due to normal vibrations. Check the memory (RAM) to be sure they are secure, as the problem of vibration can affect them as well. Lastly, ensure all of the external cables are securely attached.
Software Computer Repairs that may be Required if Hanging After Power Up
If the computer is failing to load the operating system, the problem could be as simple as disconnecting any new devices recently attached. It could also indicate a software conflict, or missing/corrupt software. In this case it may be necessary to restore the operating system from a current back up, or if all else fails, re-install the operating system.