I not sure which version of the CD you have.
I would remove any Pico driver files you have manually copied to ie (C:\Windows\system\)
And download the latest Software Development Kit from our website at:https://www.picotech.com/download/
In the right hand column click on PicoSDK 32 bit to download. Choose the stable version
The SDK installer will automatically install all the drivers into the system PATH.
The Excel example may have been updated from your CD version.
You can read this forum post for more information about SDK packages-https://www.picotech.com/support/topic18991.html
Post back if you are still having issues.