I have this same question. I have a newly-built MCE 2005 PC, and I have installed a Hauppauge WinTV-PVR-150 analog PCI tuner card in it, and hooked that up to my DirecTV R15 satellite receiver's analog outputs (via the red/white/yellow RCA cables).
I have a Microsoft USB remote receiver and remote control, with an IR emitter plugged into the back of the USB remote receiver and aimed at the DirecTV receiver.
When I go into MCE 2005's "Set Up Your TV Signal" wizard, I choose the United States as my region, and choose to Configure my TV signal automatically.
The Set-top box connection is successfully found, and I choose to configure my TV signal using that result.
I choose Satellite as my type of TV service, and when asked if I have a set-top box remote, I choose No.
When asked how many digits my highest channel received is, I choose three digits. When asked if I have to press Enter or OK after entering a channel number, I select No, I just enter the channel number.
When I'm asked to select my set-top box brand, I select DirecTV.
The next screen asks me to select a remote control code, and tells me my set-top box may use any of the 28 codes shown in a big listbox. I'm supposed to select one code, proceed to the next screen to test it, and if it doesn't work, select another, and keep trying until one works.
But none work. I'm prompted to choose different answers for the highest channel received and whether or not I have to press Enter or OK, and try the codes again.
The list includes codes S0749, S1749, S0566, S0392, S1539, S0099, S1108, S1189, S1442, S1538, S1076, S1142, S1444, S1856, S0247, S1109, S1392, S1443, S1053, S1640, S0724, S1052, S1414, S1639, S0639, S0819, S1054.
Does anyone else have a DirecTV R15 satellite receiver being successfully controlled by MCE2005, and if so, can you tell me which of these codes you used?