Step 1: Redownload CF(Sometimes the files them self wont update
Step 2: Restart your computer
Step 3: Open windows task manager and look for any un-needed/unwanted programs and stop them.
Step 4: Make sure your Anti-Virus software isn't blocking it for some reason.
If you have done all this and you still need help, I would suggest contacting z8 support. It might be faster than waiting to see answers here. Also you can try just giving it a quick google search, usually you are not the first person to experience issues.