QuickRef 3.x uses a different data format for line items, and also stores multi-user data in the same folder (unlike versions 1.x and 2.x). So if you are upgrading, there is a bit of work to do to bring in your old data.
If you have installed the new one and your old projects and notes are visible in the new one, great - go to the next paragraph. If nothing is visible in the new one, then you need to copy all the files from the old version's data folder to the new version's data folder. Start the old one and make a note of it's data directory (shown up at the top of the form when it first starts). Use Windows Explorer to copy everything from the old to the new. Note that this will over-write some same-name files that have been created simply by your starting up the new version.
Once you have the projects and notes showing, you need to convert the line item files. Select "Help, Import old version line items" to bring up this form:
Click the Select File button and find the old data files folder. The files are named time.dat, money.dat, travel.dat, time_template.dat, money_template.dat, and travel_template.dat. Select each one in turn and then hit the Merge button. A dialog will tell you what happened when the operation is complete.
If you are merging together multiple users, it is best to run the import utility on each new installation - AFTER PICKING A COMMON FOLDER! Otherwise, the program will throw up warnings the second time you import a particular file. There is no import utility for project headers - those will need to be re-created manually. Also, note files (.REC) will need to be copied manually with Windows Explorer.
There is no import utility for old DOS version records (Sorry, but you've had years to upgrade - should have thought of it sooner!).