Try pushing the wave form as much as you can digitally. I've found, on a PC, that although going too far is harsh, going too low on the visual wave thins the sound. I push it pretty hard, where it looks like it's peaking continuously, but doesn't give the cold crash sound. Some of my best distortion guitar recorded on PC was from tracks I though I'd have to throw away because the gain was too high.
It's a thin line to walk (with my system, anyway) but I have a feeling that your problem is with you being too careful not to distort the computer recording. It's a good rule to follow, but you have to break it carefully if you want your guitar to sound hard. It can be done, with experimentation. I've found the mic placement issue to be of varying small degrees of sound, but the gain can get big or small fast. Try overloading the gain and getting the PC noise, then take it back a notch. Skirting this line has given me harder, very good, distortion guitar than I ever got on tape.