Oh, and if it helps, I can say what hasn't worked so far:
Making sure I'm up to date with windows. Already was from the start, with 2 successful runs at the game (before I restarted my PC and they disappeared)
Changing microsoft accounts.
Reinstalling my store
Changing the drive it installs to, or even the default drive for the store
Backing the game up from a previously saved backup in conjunction with the tweaker
Manually deleting old install bits of the previous installs
Whatever I've tried, I still can't get the store to even let me attempt reinstallation.
also, whoops, this is the same poster as above. I have too many xbox accounts. >.>