I absolutely, whole-heartedly agree with gotty. I just wasted over 6-hrs. of my time and my husband's (he's my office IT person) at the office trying to figure out what was wrong with the system! - on a day when we should have left to go out of town between 6 & 8 a.m.
Everything was fine last night. Some time in middle of night, my Avast updated to7.0.1426. When I got up, my computer was cludgy, with all of the mouse problems gotty described. After rebooting, the mouse problem resolved itself & so did the general cludginess to some extent; however, although it said I had an internet connection, I was obviously not getting out on net. When the basics didn't work (going from wireless to ethernet, resetting router, switching to our portable Verizon router, etc.), I got hubby involved because I figured the problem was elsewhere in system (we run independent firewall, etc.) It never dawned on me that it might be Avast because I've used it for years & had never had any problems. When everything was exhausted, he told me to shut down my firewall & Avast. Quickly realized it was the Avast.
Then I started turning off the individual portions of it. The problem is the Mail Shield & Web Shield. From there, I'm still stumped. Regardless of which of the individual portions of the shield I activate or de-activate, I have no internet access so long as those shields are up. Only when they are totally de-activated can I get out. Running without the anti-virus shield, especially regarding my e-mail is unacceptable. Any ideas anyone.
I run Windows 7, Home, 6-bit; latest versions of Firefox & Earthlink. I also run Chrome at times (same problems there.)