875MB os? which one is that? I wouldnt recommend using CF or proms for their speed. They are slower than an ATA drive. The fastest thing out there is scsi 320 followed by scsi160 and then serial ata. (we will leave out the fiber channels and stuff like that). Personally, there isnt an os that cant be installed in uner 500 meg, and once your up it wont matter. You could get a board that supports linux bios. That gets your system to protected mode a lot faster and can help with boot speed. You could still boot any version of windoze from it as well. I personally use a very small custom compiled kernel with all the support I need built in. I use linux though, you cant do an install like that with windows. Good luck on you search.