Microsoft Security Essentials is a lightweight anti-virus for basic use. It is a response to complaints that Microsoft did not provide enough anti-malware and anti-virus security to its consumers. Its level of effectiveness is not comparable to industry grade security suites like Kaspersky, ESET Smart Security, or dare I say, even Symantec's solutions. You'll need to judge the pro's and con's of using MSE.
Think about this: If you are are trying to fix your guitar, do you go to a music store, that fixes guitars all day long, or do you go to a general hardware store and ask them to fix it for you? When you are having a problem with your brain, do you go to a neurologist, or do you go to a general practitioner that does not always deal neurological problems? The same can be said with anti-virus and security. There are companies that specialize in it and are recognized as world class, and then there are general companies that offer a baseline solution.
If you regularly perform data retention and back up your essential software, files, or do disk imaging, you don't necessarily need a great security suite. This also depends on how critical your data is or what would happen if it fell into the wrong hands.
If the system goes down, 9 times out of 10 you can just restore from backup. How you allocate these resources is up to you, but you should not leave yourself unprotected. Use MSE as a baseline and consider future improvements as the need presents itself. I agree that it is a case of reactionary vs. preventative maintenance and always has been.
I would like to enable windows defender on my laptop but unable to do so. Do I need to uninstall ccleaner and spybot as well as AVG antivirus?
In Windows 8, MSE is part of Windows Defender. It can still operate with most anti-virus solutions installed. I do not know why you would need to uninstall all of these programs.
Spybot is not that great compared to Malwarebytes and I would consider using Malwarebytes instead.
I would consider continuing to use AVG or migrate to Kaspersky or ESET Smart Security.