A business associate of mine is at a remote location and needs to look at autocad files. (he only needs to view R14 Autocad Light files.)
I don't know if it is still available, but years ago, we used a program called VoloView. There is also an app on my phone available for viewing AutoCAD drawings. Not sure of the name, but it is a Sprint phone.
Another option, which may or may not be an option is Primo PDF. I know it is a free viewer. You can print the files as a PDF and then save.
Try the AutoCAD Trueview app...
http://usa.autodesk.com/adsk/servlet/pc/index?id=6703438&siteID=123112
TruView on autodesk site. It will also convert newer versions down to older to open in older versions.
Free CAD software for your DWG files:
http://www.3ds.com/products/draftsight/free-cad-software/
Here's another option I've used for years
Brava Viewer