Access to my Windows "Store" is only via my Wife's MS Live Sign-In UserID and there is No Way to Change it I can Find

Question

THE ISSUE:
Whenever i go to the Windows Store on my 8.1 Pro Laptop and try to install **Anything**, Windows asks for me to sign onto my Windows Account but **ONLY** Offers me the choice of signing onto my Wife's account.
NOTES:
(1) I have already signed onto my Microsoft Account: at the time of booting into Windows on my Laptop [i.e., entered my "[email protected]' MS Live userid for signing in].
(2) There are no Options (that I can find) within the Windows Store to allow me to designate a Different ID (That is: My Windows ID [email protected], rather than my wife's Windows ID of '[email protected]').  That is, the sign-on screen comes
up **Automatically** with the UserID of my wife ("[email protected]"), ONLYT allowing me to enter the **Password** for That Particular UserId - but **Not** change the UserID
(3) When I then go to my Browser and sign into Microsoft Live **directly** with my [email protected] MS Live Userid, there are no Options **Anywhere** in my ID Profile, Account, - OR Anywhere Else [I looked at Every Menu Option for my MS Live account]
to allow me to ensure that the ID "[email protected]" is somehow an alias that I can delete, or in any other way "Tell" MS Live to ONLY use my [email protected] MS Live Account for the MS Store.  Simply Speaking: that ID [My
wife's "[email protected]" ID] does NOT Show Up ANYWHERE under ANY Menu in my Microsoft Live Account, so even if I sign [again, since it did it at Boot time also already] into my MS Live Account, there is nowhere where there is some "Option"
to somehow "Turn Off" the recognition of ONLY my wife's Microsoft Live ID from my Window's Store.
Yes, I suppose I **Could** simply ask my wife for her ID - EXCEPT Guess What?  She asked for it to be deleted when she ran into MS Login problems on her laptop (perhaps because she forgot the PW) and I've been told recently By MS Support that indeed
it has been deleted.
Sooo:  Is There Any Way To Even Manually (in the Registry or elsewhere) Fix This Issue?
[B-T-W:  I think the problem originally occurred when my wife tried to purchase MS Office 365 University and had major problems creating a MS Live ID and being able to Login to get to her machine.  Once she had purchased the subscription
- which was for TWO Machines - I used her ID at that time to try and get access to the install files for a copy MS Office 365 University to install on **My** laptop as well.  I think that is when I originally was able to input her ID ("[email protected]")
somewhere as I tried to get to Office 365, which was purchased under her "[email protected]" ID.  It Never Worked - because she forgot her password somehow, so I eventually gave up on that approach and she asked for her money back for her
purchase of MS Office 365 University and was given nit back.  Since I still wanted MS Office 365 University, I used a link from an email sent me by Microsoft to purchase, download, and install MS Office 365 University thru my OWN [email protected]
MS Live account.  But this never succeeded in "Changing" this issue I've described above of all access to MS Store coming up with my wife's "[email protected]" MS Live ID automatically to sign into the Store.]

Answer 1

FangZhou:
What I meant by the sentence "ONLY Offers me the choice of signing onto my Wife's account." is
that my Windows Store shows my Wife's OLD (I say "OLD" because according to Microsoft, it has since been deleted) Microsoft Account UserID - NOT **My** UserID, and doesn't allow for any means or option to switch out the UserID that is being presented.
 It only allows for input on the password, which won't do me any good, since my wife (1) Doesn't remember her hardly-ever-used Microsoft Account userid Password and (2) I really should be able to use my **Own** Microsoft Account UserID anyway, to which
I **do** know the password.
In any case, I ran the Troubleshooter you pointed me to (Thanks!).  But the Troubleshooter did **Not** complete successfully, because the ms-windows-store:PurgeCaches file is **Missing** (this error message came up while the Troubleshooter was running,
and also the Troubleshooter results indicated only one of the three problems it found with the Windows Store on my machine had been fixed, the principle cause being exactly because this particular file is indeed missing) ==> see the following messages cut
'n pasted from the Troubleshooter's Results:
Windows Store Apps
Publisher details
Issues found
Windows Store cache may be damaged
Windows Store cache may be damaged
<data id="Description" name="Description"></data>
Not fixed
Reset and open Windows Store
Completed
Windows Store configuration may be damaged
Windows Store configuration may be damaged
<data id="Description" name="Description"></data>
Detected
Re-register Windows Store
Completed
Some security settings are missing or have been changed
Some security settings are missing or have been changed
<data id="Description" name="Description">Some apps might not have access to required resources</data>
Fixed
Reset security settings
Completed
Now that I've run this Troubleshooter, I have a **Completely Different [and seemingly WORSE] Problem** with the Windows Store on my machine:  when I click on it, I am sent Right Back to my Windows Desktop - every time.  I don't even get Into the
Windows Store AT ALL - immediately after clicking, the screen changes back to The Desktop.
Any Thoughts on how I rebuild/recreate this Windows Store Cache file; or otherwise fix my access to Windows Store now?