X2 Stopped Exporting Audio

Hi everybody. Sonar X2 will export audio (wav or mp3) on my laptop but stopped exporting on my studio PC. The file is created but the length is 00:00. My laptop is running windows 8.2 but studio PC is Windows 7 Pro. It worked fine until recently and I suspect it's a windows thing, but I've always found help here and wanted to ask first before calling tech support. Any advice? Thanks in advance.

Hi Ken. That is really smart and something I wouldn't have thought of. However, that was not the issue, but it did give me an idea. I opened up a different project and it worked fine. I can only conclude that the file I was working with was somehow corrupt. Thank God it wasn't anything I put a lot of time into and didn't loose anything significant. I am still convinced it was a Windows thing and not Sonar.
I have learned over the years and can't stress hard enough how important it is to save and back up a project frequently. In fact, I save my projects every time I do anything to it. While I find Sonar to be stable, I can't say the same for Windows. I even survived a lightning strike once and the subsequent power surge before I could shut things down, because I save my work religiously. Thanks for offering your help.