The most likely reason LeapFrog Connect is unable to communicate with your device is a missing or improperly installed driver.
Windows
For LeapPad1, LeapPad2 or LeapPad Ultra click here
For Leapster Explorer or LeapsterGS Explorer click here
For LeapReader click here
For My Pal Scout/Violet click here
For Tag Reader on Windows XP click here
For Tag Reader on Windows Vista, 7, or 8 click here
For LeapReader Junior or Tag Junior on Windows XP, click here
For LeapReader Junior or Tag Junior on Windows Vista, 7, or 8 click here
Mac
The Mac driver can be installed or updated with the steps here
ESET NOD 32 Security
We have seen instances where ESET Nod 32 security runs a proxy scan which interferes with the sync. LeapFrog Connect requires an open connection to the internet and is not compatible with proxy servers. If you are running ESET security on your computer and experience difficulty syncing, please try the instructions below.
We suggest temporarily disabling the ESET security with these steps:
1. Click the Windows Start button, select Run, and type "Services.msc" into the Search box
2. Locate "Eset Service" and set its "Startup type" to "Disabled"
3. Restart your computer
4. Click the Windows Start button, select Run, and type "msconfig" into the Search box
5. Click the Services tab
6. Locate "egui.exe" and disable this
Then disable the proxy server with these steps:
1. On the Control Panel of the computer, click Internet Options
2. Click the Connections tab
3. Click the LAN Settings button
4. Uncheck the box next to "Use a proxy server for your LAN"
Then try syncing again.