Solution 19609: Resolving the Error "Access Denied" When Transferring Apps/OS Files Using the TI Connect™ Software and TI-84 Plus Family Graphing Calculators.
How do I resolve the error "Access Denied" when transferring an App or OS using the TI Connect software?
The error "Access Denied" indicates that the TI-Connect software could not complete the current transfer due to an unforeseen error. Please try the following troubleshooting steps if the error persists.
Perform a manual "Garbage Collect" on the calculator (TI-83 Plus and TI-84 Plus family only):
First, on your handheld press [2nd]  [TAN] [ENTER] [ENTER] .
Please Note: A manual "Garbage Collect" can take up to 5 minutes to complete.
Now attempt to transfer data to the calculator.
Uninstall and reinstall the TI-Connect software:
1) Go to Start >> Settings >> Control Panel or Start >> Control Panel and select "Add or Remove Programs".
2) Locate the TI-Connect software in the list and then choose "Remove".
3) Once the software uninstall process has completed, please shut down and power off the computer.
4) Wait approximately 20-30 seconds and then reboot into Windows.
5) Download and install the latest version of the TI Connect software from the TI Connect Software home page.
6) Once the TI Connect software install process has completed, restart the computer before using TI-Connect.
7) Attempt to transfer data to the calculator.
If the above troubleshooting steps do not work, please contact TI-Cares Technical Support for additional troubleshooting.