I have the same issue. I had a windows update since I first installed TurboTax and completed my return. Since the windows update TurboTax gives the Error 70001. I have tried uninstalling and reinstalling many times both as admin and not as admin. I have reset my router many times. I am not willing to rollback the Windows update. I called TT support and was issued a refund through Amazon. Still I have tried and tried though still 700001. I will have to switch to TaxCut. Though I have used TT for probably 20 years. Disappointing.
