I click on a link or start typing text in a box on a webpage, any page, and the browser window either randomly changes size, reduces & goes to the toolbar, or some other strange random thing occurs. Why is this?

Question

Whenever I am using Firefox, when I am on a webpage (any webpage) & I either click on a link in that page, start typing in a box, click on a button, or click on a tab, the browser window either reduces to the toolbar, or just changes size, usually from full-screen to 2/3 of its size. I reinstalled Firefox (downloaded from the web) after wiping my hard drive because I was having so many problems from my browser constantly crashing, to the computer itself crashing often, to the computer running exceptionally slow. At first everything seemed fine. But then after having opened my computer a few times, a few different windows began to freeze, then that stopped, then this thing with the browser started a few times later after opening it. Now it does it every time I open it. Also, whenever I try to click on a button on other windows on my computer, I get the 'warning' sound, nothing happens, then after a couple more tries, the button works. All of this is just weird. I had antivirus protection on my computer, but it apparently did not catch whatever virus infected my computer, or the damage was already done when it did get it. I thought once the hard drive was wiped, that everything would be ok, but then these weird things began to start up, and now I am wondering.... Of course, it could also be something wrong with the browser, too. I've also had some trouble getting my printer to working again, but I've managed to solve that problem.

Answer 1

I have had a similar problem with my system. I just recently (within a week of this post) built a brand new desktop. I installed Windows 7 64-bit Home and had a clean install, no problems. Using IE downloaded an anti-virus program, and then, because it was the latest version, downloaded and installed Firefox 4.0. As I began to search the internet for other programs to install after about maybe 10-15 minutes my computer crashes. Blank screen (yet monitor was still receiving a signal from computer) and completely frozen (couldn't even change the caps and num lock on keyboard). I thought I perhaps forgot to reboot after an update so I did a manual reboot and it started up fine.
When ever I got on the internet (still using firefox) it would crash after anywhere between 5-15 minutes. Since I've had good experience with FF in the past I thought it must be either the drivers or a hardware problem. So in-between crashes I updated all the drivers. Still had the same problem. Took the computer to a friend who knows more about computers than I do, made sure all the drivers were updated, same problem. We thought that it might be a hardware problem (bad video card, chipset, overheating issues, etc.), but after my friend played around with my computer for a day he found that when he didn't start FF at all it worked fine, even after watching a movie, or going through a playlist on Youtube.
At the time of this posting I'm going to try to uninstall FF 4.0 and download and install FF 3.6.16 which is currently on my laptop and works like a dream. Hopefully that will do the trick, because I love using FF and would hate to have to switch to another browser. Hopefully Mozilla will work out the kinks with FF 4 so I can continue to use it.
I apologize for the lengthy post. Any feedback would be appreciated, but is not necessary. I will try and post back after I try FF 3.16.6.