Before proceeding, note that there is no way to merge the data from multiple databases, so you will need to make sure you have the information to manually re-enter the sales on the correct database once all machines are correctly pointed to the main database.
On each machine, go to the File menu and make note of the Data Directory.
Once you have the data directories, you need to verify that they are all mapped to the correct machine. Open either your My Computer icon or go to Start > Computer. Under Network Location you should see the drive letter that your data directory is mapped to. It will tell you there which machine name holds that folder. All machines should be pointed to the same server machine. For any machines that are not mapped to the correct server, right click on the drive and select Disconnect. Then go through Map Network Drive to set up a mapped drive to the correct server, making sure it is set to Reconnect at logon.
All the machines should be pointed to the same folder on the server, but to verify you can create a text file in that folder on the server named THIS IS THE RIGHT SERVER.txt, then open all the mapped drives from the lane pc's and make sure they all see that file.
For all machines that had to have their shared drive remapped, delete their existing QuickStore icon, then open the new shared drive and in the WQS folder locate the file Set Up Workstation Access WQS.exe and run it. This will create a new desktop icon on the lane pc, and a new initialization file on the server machine. Each lane should have a unique filename listed for the initialization file when you check it in the File menu. If there are any duplicates, you will need to also run the Set Up Workstation Access WQS.exe on that machine.
The backups are always created on the server machine. The automatic daily backups are created in C:\WQS\BackupA. If backups are being created on different machines, it is because those machines are not all connecting to the same database on the same server. The above steps should rectify this situation.