I have Mathcad 13 installed on my computer and was getting annoyed that my kJ, kmol, and mmHg units did not exist and had to be defined at the top of every new assignment. So I found that by editing the .xml and .mpl files, the units could be added. Stupidly, I figured I would not make a mistake and did not create a backup, yet now that I have finished, Mathcad refuses to load. I get the typical application error: "Mathcad Application has encountered a problem and needs to close. We are sorry for the inconvenience." I have tried restarting my computer and everything, but the only solution I see is reinstalling the software. However, I am currently studying abroad and do not have the disc with me. I was wondering if anybody has a solution, or if anybody has the .xml and .mpl files that I have edited and would be willing to send to me...they weigh in at a combined size of under 100 KB. /mpl/mcdunitsystemsi.mpl and /units/unit-system-SI.xml Thanks in advance.