The Condense Data utility
From the article: The Condense Data utility stream lines your company data file by condensing closed transactions into summary journal entries and removing unused list elements. The utility can create a journal entry for each month in the selected period. The summary journal entries affect your accounts in exactly the same way as did the detail transactions. … and more
Error 15240: The payroll update did not complete successfully
File Exists: The file you specified cannot be opened. Make sure that it is not being used by another program.
How to fix it
This issue has been resolved in the latest release for QuickBooks Desktop 2014. If updating your QuickBooks Desktop to the latest release does not resolve the issue, try the following workarounds: …and more