I've posted this to other similar threads; hope my solution will help someone.
I was all prepared to try a reinstall of windows7 when everything went back to normal, no ctrl alt del any longer. To be certain it was not a bug, i went ahead and paid for the full version of malwarebytes and on the first scan, it did find a couple of PUP's that MSE missed. MBAM support told me that their software dolesn't like running along side MSE so i uninstalled it. They further suggested i use Avast(which i do love) and together they seem to do a good job.
I said all that to say this; the mouse thing still lives! Then after reading online for hours, I thought to install a program designed to work with my Logitec thumb roller mouse. I played around with the different configurations, didn't find them useful so i set it all back to default. This program is called the logitec Setpoint. I've left this program running and have not had the mouse click problem since!
Perhaps, on any brand of mouse, you could find and install software/drivers designed specially for you mouse. Apparently the plug and play windows 7 default drivers are buggy.
Good luck all