How to restore Google Chrome:
1. Close the Google Chrome browser, if it is running.
2. Go to Start menu, search for Run and open it. Or find it out from the Start menu, All programs, Accessories.
3. Type the following line according to the OS in the run box.
%LOCALAPPDATA%\Google\Chrome\User Data\ (in Windows 8/7/Vista)
%USERPROFILE%\Local Settings\Application Data\Google\Chrome\User Data\ (in Windows Xp). And hit Enter.
4. There is a folder named Default and this folder contains all the current settings.
5. Rename the Default folder to Default.old.
6. Now lunch the Google Chrome.
See, all the original settings are restored. A new folder "Default" will be created and it will hold all settings for now.
How to restore Internet Explorer in Windows 8:
1. Swipe in from the right edge of the screen (if you're using a mouse, point to the upper-right corner of the screen and move the mouse pointer down), and then tap or click Search. Enter Internet options in the search box, and then tap or click Settings.
2. In the search results, tap or click Internet Options. Tap or click the Advanced tab and then tap or click Reset…
Note: Select the Delete personal settings check box if you would also like to remove browsing history, search providers, Accelerators, home pages, Tracking Protection, and ActiveX Filtering data.
3. In the Reset Internet Explorer Settings window tap or click Reset
Note: To delete all personal settings,tap or click the checkbox for Delete personal settings.
4. Close and then restart Internet Explorer for the changes to take effect.
How to restore Internet Explorer in Windows XP, Vista or 7:
1. Exit all programs, including Internet Explorer.
2. If you use Windows XP, click Start, and then click Run. Type the following command in the Open box, and then press Enter: inetcpl.cpl
If you use Windows 7 or Windows Vista, click Start
Type the following command in the Search box, and then press Enter: inetcpl.cpl
The Internet Options dialog box appears.
3. Click the Advanced tab.
4. Under Reset Internet Explorer settings, click Reset. Then click Reset again.
Click to select the Delete personal settings check box if you also want to remove browsing history, search providers, Accelerators, home pages, Tracking Protection, and ActiveX Filtering data.
5. When Internet Explorer finishes resetting the settings, click Close in the Reset Internet Explorer Settings dialog box.
6. Start Internet Explorer again.
How to restore Firefox:
1. At the top of the Firefox window, click the Firefox button, go over to the Help sub-menu
and select Troubleshooting Information.
2. Click the Reset Firefox button in the upper-right corner of the Troubleshooting Information page.
3. To continue, click Reset Firefox in the confirmation window that opens.
4. Firefox will close and be reset. When it's done, a window will list the information that was imported. Click Finish and Firefox will open.