Note this help document is for older versions of Logger Pro.  If you are running a recent version of Logger Pro (3.12 or newer,) see here: Are the device drivers installed correctly? (For Windows with LabPro, original LabQuests, LabQuest Mini, and LabQuest Stream)

If Logger Pro cannot find hardware, check the device drivers first:
Windows Pre-Logger Pro 3.11 original LabQuest and LabQuest Mini, and pre-3.12 LabPro drivers
If the device drivers are broken, then fix that first.

If the drivers look right, check the file size of the “wdapi921.dll” file, (in the same folder as the exe file, so something like “C:\Program Files (x86)\Vernier Software\Logger Pro 3″) On 64 bit machines that file should be 108KB, on 32 bit machines it should be 140KB.

If it is the wrong version, you can find both files under the LabPro SDK:
Look in the redist\LabPro_console\win32 folder, rename and replace as appropriate.