Your CPU doesnt support long mode.

I have installed ESXi 4.0 server as a host on Dell OptiPlex 755 with 4 GB ram(Intel Core2 Duo E4600@2.4GHz

2.39 GHz).I am using 32-bit system.Now I also installed vMA and when I am put the power on,it is throwing the following error on the console  --

Your CPU doesnt support long mode.Use a 32-bit distribution.

I checked some forums and found out that  VT should be enabled in BIOS and when I check my BIOS setting and make the following changes-

Performance > VT for Direct I/O Access(set toOn)

but getting the same error..

please help me to resolve it...

Thanks in Advance.