Win8 is able to install Third-party anti-virus software, for can not install some of the famous anti-virus software abroad, the reason should be compatibility, domestic anti-virus software compatibility is very good, can accommodate multiple software without its conflict, and foreign some of the cheap can only tolerate a computer anti-virus software.
There are currently two possible reasons, one is the domestic anti-virus software uninstall is not clean, we recommend that you check whether there are software residue files, preferably for System Restore, restore to install the software before, such words will not have any anti-virus software residue files.
If the problem after the restoration is still the problem with the WIN8 anti-virus software, Windows Defender, Windows Defender is Microsoft's own anti-virus software, want to install other software compulsory uninstall said is off. Close the method is also very simple, click the Start button, open the Control Panel, click on the top right side of the view to choose a large icon, select Windows Defender, point tool options, in the administrator, cancel the use of this program on it.