Browser window closing unexpectedly.....?

I assume you are using IE7 so try the following, First run a virus scan/spyware/hijacker etc if you have not done so far, you could also try:

Use the usual methods to identify the third-party software that produces

your problem:

1. run IE with "No Add-Ons"

2. disable third-party extensions in Internet Options/Advanced

3. boot Windows in safe mode

If any or a combination of the above solves your problem there is

third-party

software responsible for your problem.

If 1.: use Add-Ons-Manager and disable all non-Microsoft add-ons and

reenable them step-by-step until your problem comes back

If 2.: that's likely a toolbar or some other installable add-on like a tool bar

If 3.: that's likely a third-party software run from startup that can but

doesn't need to have "visible" connections to IE, for instance

a so-called desktop search.

also try

http://support.microsoft.com/default...;EN-US;q268...

http://support.microsoft.com/default.aspx/kb/92139...

1. Does this behavior persist if you start IE7 in No Add-ons mode?

To start IE7 in No Add-ons mode:

Right-click on the blue IE desktop icon and select Start without Add-ons; or

Start > (All) Programs > Accessories > System Tools > Internet Explorer (No

add-ons).

More:

Troubleshooting and Internet Explorer’s (No Add-ons) Mode:

http://blogs.msdn.com/ie/archive/2006/07/25/678113...

2. Does the problem persist if you Reset IE7 Settings (RIES)?

http://support.microsoft.com/kb/923737

3. If you uninstall IE7 (which automatically returns you to IE6), does this

behavior persist?

Uninstalling IE7

http://www.ie-vista.com/kbase2.html

How to uninstall Internet Explorer 7:

http://support.microsoft.com/kb/927177

IE7 (Un)Installation and Anti-Malware Applications:

http://blogs.msdn.com/ie/archive/2006/10/11/IE7-In...

There may be other causes

I have noticed that Firefox crashes and closes more than Internet Explorer. Certain sites always cause Firefox to crash. But in general I like the feature of Firefox better, especially tabbed browsing.