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Question (Q&A-73|250): I can not virtual 64bit OS, when I adopt AMD® CPU with Sun's xVM virtual Box software. How can I do?(6/25/2009)
Answer:1. Please make sure your OS is 64bit and also check your CPU, whether support AMD-V.
2. [Enable] [Secure Virtual Machine] option in the BIOS.
3. Please check the [Enable Nested Paging] box in Sun's xVM virtual box software.

And then you can virtual 64bit OS.