We have already seen that you can take Windows 8 with you on your USB drive using the Windows To Go feature. Now since you can carry Windows 8 as a portable operating system, you may need to make some additional settings as well. We have observed that when you move your screen to Windows Store on this portable Windows 8, you might find that Store is inaccessible. The following is the display you may see instead:
Windows Store isn’t available on Windows To Go workspaces

Then how do you access Windows Store on Windows To Go? Well if you are using Windows 8, then you additionally need to configure the setting and you will be able to use Windows Store. However, if you’re using Windows 8.1, then you won’t have any problem in getting Windows Store because settings are already configured in this updated operating system. So Windows 8 users, please follow this tutorial:
Using Group Policy Editor
1. Press Windows
Key + R combination, type put
gpedit.mscin Run dialog box and hit
Enter to open the
Local Group Policy Editor.

2. In the left pane, navigate here:
Computer Configuration ->
Administrative Templates->
Windows Components ->
Store
3. In the right pane look for the setting named
Allow Store to install apps on Windows To Go workspaces, it must be showing Not Configured status by default. Double click on the policy to get this:

4. In the above shown window, click
Enabled then
Apply followed by
OK. From the policy explanation it is clear that this setting will only work for with single PC and not supported in case of multiple PCs. You may now close the Local Group Policy Editor and thus now you can access Windows Store on Windows To Go.
If you’re using Windows 8 Home edition, then you won’t be able to access Local Group Policy Editor, so the above mentioned method is infeasible for you. Thus you can head on to Registry Editor:
Using Registry Editor1. Press
Windows Key + R combination, type put
Regedt32.exein
Run dialog box and hit Enter to open the Registry Editor.

2. Locate this key:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsStore
3. In the right pane of this location, right click and select
New ->
DWORD Value. Name this newly created DWORD as
EnableWindowsStoreOnWTG. Now double click the same DWORD to get this:

4. In the above shown box, type the Value data equals to
1 in order to make Windows Store accessible. Click
OK. You may now close Registry Editor can connect to Windows Store on Windows To Go now.
source:twc