Why my mouse do not always right-click?

My PC is Windows Xp Professional and sometimes the mouse easily right-click, then sometimes it will not. All my adware,spyware, anti-virus are showing no attack, I have up-todate protectors, lavasoft,mcafee, spy terminator,and firewall. The mouse was clean of dust inside and it work for a while then stop.One time I accidently was in ''safe mode'' and it work perfectly, then my PC informed me that I was in ''safe-mode'' and had to go back to system restore.What is the problem? Could I have accidently erase something?Thank for any sound advice.

Why my mouse do not always right-click?antivirus software

no, you couldnt have erased anything, unless you were just deleting random drivers out of your system32 folder, which i bet you weren't.

try pressing the left button on an empty area. does it work like the right button all of a sudden? if it does, press the left alt button on your keyboard a bunch of times. i know it sounds stupid, but it worked for me. i couldnt begin to explain why because holding alt and left clicking does not act like a right click.

other than that, got me. try resetting.

about safe mode:

safe mode is a different shell in windows. when you dont shut down properly or reset the computer without using the windows start menu, windows thinks something absolutely must be wrong with your computer and suggests you search for the problem in safe mode, which does not load all of the drivers and linked libraries that the standard windows shell does. safe mode does not require going back to system restore. you just restart the computer to get out of safe mode.