Installing pfSense (current version 2.2.2) on a Dell Poweredge 1850 is not as easy as one would think. The installer seems to hang on 38% and there’s nothing you can do about it! … Well actually there is!
I’ve spent several hours dealing with this weird issue and found out from various forum posts that if you disable both NIC’s in BIOS as well as CPU specific settings such as Sequential Memory Access you can get past this problem. Also some people have had success using Option 99 after booting into pfSense Live.
Third and equally important (in my case) is that when you hit the install button quickly unplug your keyboard, I know this sounds strange but it worked in my case. I’ve read about other people also having luck with a PS/2 keyboard.
Now you may get tempted to cancel the installation because it’s taking too long at 38% but trust me (found out the hard way), it will work eventually!