After installing some software, our computer will always have a little change, not on the desktop more than a few URLs icon, IE browser's default homepage was tampered with the Web site. The most exasperating is, in IE settings will be the default home page changed back, the next time to start Win7 and then changed back! If the IE default homepage is not returned, it must be the default home page entry in the WIN7 system registry has been tampered with. In order to prevent this happening, we must first strike for the strong, directly locked Win7 system registry. When you disable access to the registry, you can not only effectively prevent changes to the program, but also better protect your computer, but only if you have administrator privileges.
Log in to an account with administrator privileges, type the command in the Start search box: Gpedit.msc, enter.
If you eject the User Account Control window, allow it to continue.
Open the Group Policy Editor. In the directory window on the left, navigate to User Configuration > Administrative Templates > Systems.
Click System, locate the Block Access Registry Editing tool from the right Detail window, and double-click to open.
The default state is "Not configured," where we set it to "enabled," and then click OK to save the changes.
It's OK! Reboot the computer and test, the Win7 will pop up when you open the registry. This, the changes to the program settings will not be easy to take effect!
If you want to undo the disabling, the action method is also simple, again configure the Block Access Registry Editing tool to Not configured.