That's an interesting problem. It sounds like you might have malware / spyware / spamware installed on top of your browser. There really is no reason for a tab to ever be locked.
If you love Google and heavily use their services I recommend Google Chrome, it's great. https

/www.google.com/chrome/browser/
If you hate Google for whatever reason then use Mozilla FireFox, it's pretty good. http

/www.mozilla.org/
If you're hellbent on running Internet Explorer then here are your options:
Get IE 11 for Windows 7:
http
/www.microsoft.com/en-us/download/internet-explorer-11-details.aspx
If you're running Windows Vista, which is the only other OS capable of running IE 9, then you're pretty much screwed, either migrate to a newer version of Windows or switch to FireFox, but just so you know, no one advocates the use of Windows Vista, it's just horrible. You'd probably get much better performance from your system switching to Windows 7, and even more so by switching to Windows 8/8.1
Other Popular Alternatives are Opera: http

/www.opera.com/
Also I highly recommend downloading, installing and running Microsoft Security Essentials:
http
/www.microsoft.com/en-us/download/details.aspx?id=5201
AND looking through your installed programs to see if you have any IE toolbars installed
Good Luck!