How turn on htpc?

Well with an htpc you don't actually turn it off, you put it in standby/sleep when not in use. Most motherboards will still be monitoring the usb ports in standby so an IR reciever/remote control will wake it. Same as moving a mouse or hitting a key on the keyboard. The case has nothing to do with it so not sure why you mentioned that.

I leave my HTPC running 24/7 eventhough I power down the display in the Power Management settings. In the BIOS I have set it to respond to ANY keyboard press to power on the PC which (if I ever have it off) will power up from the keyboard - the PC is on an out of the way shelf, high in my equipment room so pressing a button on the case isn't exactly accessible. This works with my IR keyboard as well, so I think the answer is YES.

I put my HTPC in hibernation, but physically awake (push the power button) to wake it. I am using a usb keyboard so figured it would not wake it so have not tried to wake it with the keyboard. Where in the Bios do I make the change to respond to ANY keyboard press?

Also you mentioned that you power down the display in the Power Management settings. Doesn't this power down when it hibernates? I am using Win7 if it makes any difference.

Related question: I use the IR Blaster that came with my Hauppauge 2250 for my HTPC, along with a bluetooth keyboard and mouse. None of them seem to wake the computer from sleep. Is there a setting I am missing somewhere to have my PC monitor the USB ports for activity? (Win7-64)

With my IMON receiver I can turn it on and off with the remote...literally. No button pushing on the computer itself. I wouldn't however recommend IMON though since support is pretty crappy.

Your best bet is to read the manual for your MB and see if it says which power states it supports to wake from on USB ports, not very many support wake from S5 on USB ports, S3 is more likely but many will only support S1. If your manual doesn't specify what power states it supports to wake on via USB then you'll need to just test them once you turn them on, your manual will will also give you at least an idea of what settings to set in the BIOS if not the exact setting (it may be as simple as setting wake on USB to enable or require enabling wake on PCI devices or similar). Also I've seen MBs that have jumps to enable +5VSB on USB ports. There are also IR receivers that get power straight from the +5VSB on the PSU (normally the internal ones including the OEM ones that come in HTPC case) which is nice if your MB doesn't support it on it's USB port and you don't want to replace your MB in order to turn it on via remote.

Per the manual for the Intel MB DP35DP it has this. So I guess this means it will open via my wireless USB keyboard? Is this correct?

" Wake on USB, PCI Express, LAN, and front panel"

Yes, if your USB keyboard also supports it(some wireless ones don't), however it doesn't say which power states it supports for each(may be stated someplace else) so for example USB might only support wake from S1-S3 and not S4/5.

Can't say exactly where in BIOS but it's where you're assigning the function of the power button, whether it's INSTANT or 4-second delay... that page which depends on YOUR BIOS on your system... just look and you'll find it. Since I don't do any hibernation or sleep I just use the Win 7 management setting to conserve display after 3 hours although I use Cool-N-Quiet and allow the CPU to throttle down its clock - X4 @ 3.48GHz runs at 969 MHz most of the time! It's just adjusting the multiplier to throttle down...

To answer simply would be yes it can power on using a WMC Remote. The key as someone else mentioned is to put it to sleep not hard off. Also as already mentioned, if you must go hard off than the IMON will work, but I don't like it either. To me get a WMC remote, a Harmony Remote, and enable your BIOS and USB ports to wake from USB and you are in the money. All you have to do is program the Harmony using the WMC remote and the Harmony will send the power on signal when you push Watch a Movie. It will also power down to sleep when changing to Watch TV or simply selecting the power off button. Moral of the story is put the machine into sleep, I believe S3 sleep.