In Short QBWin.log file keeps a record of all the errors that has happened in your Quickbooks file.
Below are the steps to access the qbwin.log file
With your QuickBooks Company file open, press the F2 key to display the Product Information window
Press the F3 key to display the Tech Help window.
Select the Open File tab.
Scroll down the list of files until you find the QBWIN.LOG file.
Click once on the file name to highlight it in notepad
Identification of QBWin.log Errors
Locate the error between “Begin Verify Log” & “End Verify Log”
QuickBooks data verification is a two different process. The first step is express validation of the integrity of the database, The damaged transaction shows up in between the logs.
& to fix the file you may have to edit the transactions. If editing dosent work you might have to delete & re-enter the transactions.
Errorrs might also show up as
more LVL_ERROR problems result in the inability to verify your QuickBooks data file. These errors can also result in either an ‘error message’ or a ‘fault’ which causes QuickBooks to close.
The following are examples of the kinds of errors you might see in a QBWin.log file. Remember to always back-up your data prior to performing any procedures to repair data corruptions.