A domain and a server are overkill for a three-PC office — but so is typing passwords all day. There is a neat middle path: if both PCs know the same username with the same password, Windows logs you in silently. Here is how that works, and where it stops being a good idea.
Big companies use a domain: one server holds every account, and any PC trusts it. A small office has a workgroup — every PC keeps its own accounts, and the file PC only trusts logins it knows. The so-called “same username trick” is not a hack at all; it is simply how Windows authentication naturally behaves when the two PCs' account lists happen to match.
lusrmgr.msc), each with a real passwordTo connect with an explicit account — useful when your daily login is different — use a mapped drive or the command line: net use Z: \\OFFICE-PC\Billing /user:OFFICE-PC\Ravi. Enter the password once; tick remember, or add /persistent:yes, and the drive returns at every sign-in. If a wrong login is stuck from earlier attempts, clear it first with net use * /delete and remove the saved entry in Credential Manager.
The trick has one maintenance debt: passwords must stay in sync by hand. Change the password on the file PC and every saved copy elsewhere is wrong until updated — expect a round of "access denied" until each PC's stored credential is refreshed. In a two-or-three PC office this is a minor chore once or twice a year. Past roughly eight or ten PCs, the chore becomes the reason offices graduate to a small server or a NAS with its own central accounts.
Some offices give up per-person accounts on the file PC and create a single account like office-share that everyone connects with. Be honest about what that buys and costs: setup is trivial, but permissions can no longer tell people apart and auditing names one shared account for everyone's actions. For a folder of truly common files that may be acceptable. For billing, HR or anything you would ever need to trace, per-person accounts are worth the extra ten minutes.
The video sets up complete workgroup sharing on real PCs — accounts, groups and silent logins, end to end.
▶️ Watch Full VideoPoorly. Microsoft-account sign-ins do not pass through to a local file PC account in the same clean way. For sharing, create local accounts on the file PC and connect with those (saved credential or net use), whatever the person uses to sign in to Windows itself.
Yes — five PCs is comfortably workgroup territory if one PC holds the files and accounts are kept tidy. The pain point is not the count of PCs but the count of people times password changes; central accounts start winning around eight to ten regular users.
That PC's stored credential is stale or its login does not match. Remove the file PC's entry in Credential Manager, disconnect sessions with net use, then reconnect and save the correct credential.