Windows 8 apps not working

Hi,

I suddenly have issues with my laptop not running any Windows 8 apps. If I try to use PC Settings, App store etc the machine flicks straight back to the desktop and won't go into those apps.

I have no idea what has caused it. The only thing that I have installed/changed is installing IObit malware fighter and ASC which shouldn't cause this.

Suggestions?

TIA, Tam

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8.1 Pro, 64 bit
Processor: AMD A6-3420M APU with Radeon(tm) HD Graphics, AMD64 Family 18 Model 1 Stepping 0
Processor Count: 4
RAM: 7656 Mb
Graphics Card: AMD Radeon HD 7600M Series, 1024 Mb
Hard Drives: C: Total - 307623 MB, Free - 193019 MB; E: Total - 324121 MB, Free - 323952 MB; F: Total - 58054 MB, Free - 47370 MB;
Motherboard: ASUSTeK Computer Inc., K53TK
Antivirus: Windows Defender, Disabled