To add a guiding verical line for the length of the lines in Visual Studio do as follows:
- Open registry editor
- Navigate to HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\*.0\Text Editor (* depends on your version of VS, 8.0 = VS 2005 and 9.0 = VS 2008)
- On the right pane add a new string value and name it "Guides"
- Double click on the newly created string value "Guides" and put the following as its value "RGB(255, 20, 147) 80" including the apostrophes. The string specifies two properties – RGB(255, 20, 147) – the color of the line and 80 the line length. You can adjust them to suite your needs.
- Close registry editor and restart the Visual Studio.