I can imagine how challenging this situation must be for you, especially after setting up your new computer and restoring your backup file. I'll explain some possible reasons why your item status might has changed, and we can perform a mini-reconciliation to fix this. We got this together, Beryl. 

Reconciled transactions may show up as unreconciled for several reasons:

• Someone may have undone the last reconciliation.
• Someone changed or deleted the reconciled transactions.
• Cleared transactions were unchecked (uncleared) in the account register.
• Company file conversions from QuickBooks for Mac to Windows or QuickBooks Online to Desktop (US only) can cause issues.
• The transactions were never reconciled in the company file, possibly because it was restored from a backup. This process can overwrite data and reconciliations.

To fix your case, we can perform a mini-reconciliation. This process involves setting an off-cycle reconciliation date to make corrections, assuming you have the ending balance from the most recent reconciliation. Before you start, ensure to obtain this information. I also recommend consulting your accountant when undertaking this process.

Here is the step-by-step guide to follow:

1. Head to the Banking menu and click Reconcile.
2. Choose the credit card account with the transactions you need to reconcile.
3. In the Date of Statement field, enter the date for an off-cycle reconciliation. It can be any day between your last reconciliation and the next scheduled one.
4. From the Ending Balance field, enter the balance of your last successful reconciliation. Then select Continue.
5. In the Reconcile window, check off the transactions you are fixing and re-reconciling.
6. Ensure the Difference field shows $0.00.
7. Once everything appears correct, hit Reconcile Now.

For more detailed information about this process, refer to this article: Reconcile previously deleted and re-entered checking or credit card transactions.

Additionally, you can generate a Previous Reconciliation Report to obtain detailed information that will assist in identifying discrepancies.

For future reference, you can close your books in QuickBooks Desktop to prevent accidental changes to transactions from previous periods, maintain a clear audit trail, and facilitate smoother year-end processes. 

Taking the mini-reconciliation approach and consulting with your accountant is the most effective strategy to resolve your unreconciled transactions. We're still here to help you if you have further concerns, Beryl.