It is a very common situation, you or an acquaintance receive a DWG file or you need to share a DWG with someone. You can download the free AutoCAD DWG TrueView. DWG TrueView is based on exactly the same code as AutoCAD, by the same company Autodesk.

2D and 3D DXF / DWG files are supported from AutoCAD 2.1x to AutoCAD 2012 created DWG files - spanning almost 30 years.

Highlights beyond View & Printing of a DWG:

• Convert DWG file versions including being able to bind Xrefs, Purge, set default printer to “none”, audit and fix, replace page setups, and place all files in a Zip file or specified directory.
• Change Visual Styles
• Publish files as DWF and PDF files
• Measure objects
• Turn on/off layers

So, a free DWG Viewer and DWG Conversion tool based on the same AutoCAD code, and all for free no strings attached.

The download is 270Mb and available in Windows 32 or 64 bit
Languages: English, French, and Japanese
http://www.autodesk.com/dwgtrueview

If you don’t want to install a desktop program, or just want to view DWG files on the web or your mobile devices, checkout the free AutoCAD WS and AutoCAD WS Mobile. AutoCAD WS does not have everything that the desktop based DWG TrueView has but it allows for easy viewing, markup, and sharing with others for free. You can take your DWG files with you into the field even without having a web connection to review and markup your DWG files from your mobile phone or tablet.

Two powerful solutions for viewing and printing DWG files - and both free.

Cheers,
Shaan