Open the Arduino IDE's installation folder (usually C:\Program Files (x86)\Arduino)
In the folder listing of the Arduino IDE installation folder, hold the Shift key while clicking the right hand button on the mouse.
Click “Open PowerShell window here” (or “Open command window here” if using Windows 7). PowerShell (or cmd if using Windows 7) will now open with the current directory set to the Arduino IDE installation folder.
Type ./arduino_debug
Press Enter. Debug output should now be printed to the PowerShell window as the Arduino IDE starts (or fails to start).
Wait for the Arduino IDE to finish starting, or failing to start.
Switch back to the PowerShell window if the Arduino IDE window took the focus.
Right click on the title bar of the PowerShell window.
Click Edit > Select All. This will select all the text in the PowerShell window.
Press Ctrl + c. This will copy the contents of the PowerShell window to the clipboard.
In this Arduino forum thread, click on the reply field.
Click the </> button on the forum toolbar. This will add the forum's code tags markup to your reply, making it easier for us to read.
Press Ctrl + V. This will paste the output between the code tags.
Move the cursor outside of the code tags before you add any additional text to your reply.
Click the "Post" button.
Hopefully that will give us some information we can use to help you with the problem.