Mars - I have a little bit of a similar situation, in that I had to work at home and use my company's version of QB:  2019.  I already have on my computer V. 2016, which I use for a different - very small - company.  I was told by the accountant not to upgrade v.2016 to v. 2019.  I did not and everything works.  My problem is that - I guess - when I installed V. 2019 I saved all the files to my Desktop.  Now I have 14 v. 2019 files on my desktop, showing in properties as D:.  My v. 2016 shows as filed in  OS C: Users/Public/Public Documents/Intuit/QuickBooks/Company Files.  Is there any way I can change the file location for the QB 2019 files?  BTW, I prefer NOT to put them in my documents, due their size.  Thank you!