I have change the registry window and now it is 24 Bits.
For 32 Bits, I must configure RDP? But in option of RDP, 32 Bits is configured
this is a limitation of the RDP protocol. 32-bit will never shown up in winxp/win2003.
I see absolutely no reason why 24-bit is not enough. if you configure the registry key (4) 24-bit works instead of 16-bit maximum.
but anyway, all these are microsoft issues so please go to Microsoft support in this case if you have further questions.