You don't have to close Daemon Tools, you just have to have the real DVD in your real optical drive.
2. "Insert Disk: Crysis DVD" error
* Turn off virtual tools such as Daemon Tools
* Repair Crysis installation
* Re-Install Crysis
Only if you are using a pirated version would this be an issue.
Even YASU doesn't work for hiding DT from Crysis anyway (not with the latest DT Lite that is)
* Turn off virtual tools such as Daemon Tools
* Repair Crysis installation
* Re-Install Crysis