When you try to Copy Disk a second time, the Diskcopy.dll library issues and access violation in the Rundll32.exe process.
To workaround this issue, use the diskcopy command:
diskcopy \[drive1: \[drive2:\]\] \[/v\]
where drive1: is the source disk and drive2: is the destination disk. The /v parameter verifies that the information is copied correctly, which will slow the process.