If your old Enterprise file is healthy, Intuit’s New Company from Existing Company File option can copy basic lists COA, customers, vendors, items, employees, but it will not fix size or corruption issues. In cases like yours 1.6GB and corrupt, the recommended approach is to start a brand-new company file with a start date of 01/01/2026 and bring over opening balances only, not history. Recreate or import lists as needed, then enter balance sheet opening balances as of 12/31/2025 via a journal entry (offset to Opening Balance Equity). AR/AP should be entered as summary balances or one invoice/bill per customer/vendor dated 12/31/2025.
Payroll must be set up after balances are entered. Use Ctrl+Alt+Y in QuickBooks Desktop to enter YTD payroll amounts as of 12/31/2025 and record prior payroll tax payments; there’s no supported way to import full payroll history. Keep the old file read-only for audit and reference. If the old file is too damaged to reliably extract balances, some users attempt a read-only repair on a copy to pull data Third party tools like Stellar Repair for QuickBooks can help in cases of logical corruption but the new company should remain a clean, fresh file to avoid carrying issues forward.