First check our FAQ section for your problem. There are a lot of tips and generic solutions to the most common issues. If there is no information available regarding your problem, then continue reading...
try to isolate the problem and reproduce the steps it took for it to occur. In order to resolve the issue, we must know how it originated. If an error message was displayed, please send us a screen shot of it (the best way is to use the Print Screen key with the help of any image editor).
make sure you are using the latest version available. Your problem might have already been resolved