Option 1: Check the System Time Date is correct
– Press the Windows key + C to open the Charms bar and search for Date and Time

– Click on the Date and Time result, the Date and Time window will appear, you can see the time zone is displayed correctly, if not exactly change it by clicking Change time zone. ..

– In the Time Zone Settings window, click your time zone and click OK

Or you can go to the Internet Time tab on the Date and Time window, then in the new window click on Update now to synchronize the time on the system.

Done the operation you please visit the Windows Store again? If not, you can do it the following way
Method 2: Disable Proxy Server
– Open up the IE browser, click on the gear icon and select Internet options

In the window that appears, select Tab Connections and click on LAN settings

– Remove the Use a proxy server for your LAN (These settings will not apply to dial-up or VPN connections) and click OK

Option 3: Log In And Use The Other Account On The System
Log out and then log back in with your account, and transfer from your Microsoft account to your local account

– Press Windows key + C and go to Settings -> select User -> click on Switch to a local account

The articles you can refer :

Method 4: Refresh the computer
If you have done all three ways and still have not accessed the Windows Store, you can do Refresh your computer. However, this will restore the system to its original state, so some of the software you install on your system may no longer be available.
Access and Charms bar (Press Windows key + C) -> Settings, select General -> Click on Get started and perform the task to refresh the computer.

As part of the article, I have shown you how to fix Windows 8 / 8.1 inaccessibility errors. Hope this little trick will help you in the process of using the computer.