Run As Administrator
Right click on the icon and launch Dynamics as administrator.
Security
Open windows explorer, right click on the GP install folder and choose properties. Click on the security tab and grant the 'users' group 'full control'
Read the error logs
In a recent install that had this issue, I opened the Dynamics directory and sorted the files by date modified. I found a file called installerrors.txt that had the issue in it - the chunk file that I was trying to import was not compatible with the current version.
Permissions
In the security dialog mentioned above, press the 'advanced' button and change the owner of the folder to a Domain Admin account. Sometimes the owner can be an obscure system account, I've had issues with that.
