The title for the most popular software based accounting and bookkeeping solution in the industry has to go to QuickBooks. There is a reason why it is so well loved by home users and professional accountants alike: it is extremely user-friendly while at the same time retaining advanced and powerful features that make short work of any accounting and bookkeeping tasks.
WHAT IS THE INVALID PRODUCT NUMBER ERROR?
Because QuickBooks is advanced software used by a wide number of people, not all of them with extremely high technical expertise, software errors that prop up can be difficult to diagnose or fix on their own. Of the numerous issues that can happen in a customer oriented software package, the Invalid Product Number error designated by error code 176109 is probably the most insidious.
If you are seeing this error and code on your system, it means that important authentication files on your computer system have been corrupted or deleted, causing problems in QuickBooks to start up normally.
WHY THIS ERROR OCCURS
The unique product key or product code used to install QuickBooks Point of Sale for Desktop is incorrect or invalid as authenticated by QuickBooks servers
The Point of Sale Entitlement folder has missing contents or important files
QuickBooks does not have the adequate permissions to access key files on the Windows system
PROCEDURES TO FIX THE ERROR
There are two ways you can go about for fixing the situation. However, because these methods require you to manually manipulate file contents in system folders, you should take care and precaution. Follow the instructions to the letter and do not deviate from what is given under any circumstances. Inability to properly follow the instructions can cause your QuickBooks software to end up completely unusable.
Method 1: Reset the Point of Sale Entitlement folder
Open My Computer. Navigate to the given folder with the path: C:\Program Data\Intuit\Entitlement Client\v8 If QuickBooks is running in the background, exit the application. For better chances of success, you should probably restart your system prior to proceeding further.
Delete all the contents in the folder by pressing Control + A and pressing the delete key. Alternatively, you can select the contents with your mouse, right click, and select Delete.
Restart your system to complete the process.
If the error is not resolved, try out Method 2.
Method 2: Rename the WSActivity file
Open My Computer and navigate to the given folder with the path: C:\Program Data\Intuit\QuickBooks Point of Sale XX\Ini If QuickBooks is running in the background, exit the application. For better chances of success, you should probably restart your system prior to proceeding further.
Rename the WSActivity folder by pressing the F2 button or Right clicking on it and selectingRename.
Rename the folder to something likeOldWSActivity.
Restart your system and perform Method 1 again.
These methods should ensure that your problem is fixed. QuickBooks is a very versatile piece of software and any error can be easily fixed most of the time. If you cannot fix a problem yourself, call QuickBooks support phone number and they can definitely help you figure out the situation.