Freezing screen is one of the most irritating problems. If your are working on some important projects and suddenly computer stop responding, your reaction is understandable.
The causes behind freezing screen can be complicated or simple. At many times the reason in the virus infection. So scanning with updated and good antivirus may help you to get out of this problem.
Some time you need extra memory, in that case you have to add additional RAM to your system. If there is no virus or malware detected or if they are found and fixed, but still your system freezes, then you need to check memory and hard drive. In any of these cases, it will be suggested to take help of a computer technician or one of your friends who is more knowledgeable. They will diagnose it in better way and fix it.