Try booting to
Safe Mode with Networking, see how things behave.
If the problem goes away then something is starting at boot time that is causing the problem, or a Internet Explorer Add-on is causing the problem.
Boot normally, then start IE without Add-ons.
Click on
Start, type
iexplore -extoff and press
Enter.
You will get an IE window like this:
Click on Home to go to your normal Home page. See how things are. If okay then use Tools / Manage Add-ons to disable them a few at a time till you find the culprit.
If that doesn't make any difference then
Use msconfig to determine what is causing the problem
This is a good tutorial on using msconfig in Windows 7:
How to use msconfig in Windows 7
Click on
Start, type
msconfig and press
Enter.
Click on the
Startup tab, record what is currently starting then click the
Disable All button.
Reboot and see if it runs better.
If yes then use msconfig to enable several items at a time till you find the culprit.
If no, start msconfig and click on the
Services tab.
Check the
Hide All Microsoft Services box, record what is currently starting then click the
Disable All button.
Again, do a regular boot, see if it runs normal.
If yes then use msconfig to enable services till you find the culprit.
Once you've found the culprit, uninstall it or find out how to eliminate it from your system. Simply disabling it in msconfig is a temporary fix at best.
Enable everything else you disabled.