Use DrawCompare to compare all entities between two drawing documents. The differences between the drawings are displayed in color codes. You can also compare a detached drawing to its associated fully-loaded drawing.
DrawCompare compares
the bitmaps of two drawings at the bit level. Only visual changes are
captured when the drawings are compared. For example, if you move an annotation
2mm to the left, this change is reflected in the comparison. Conversely,
if you change a custom
property such as the Description,
this does not reflect in the comparison.
To use the DrawCompare tool:
Click Tools, DrawCompare.
For Drawing 1, click Browse to locate a drawing.
Click Change
Drawing 1 Color 
to change the color used to display
the differences in drawing 1.
Repeat step 2 for Drawing 2.
Click Change
Drawing 2 Color 
to change the color used to display
the differences in drawing 2.
Click Compare
Drawings 
.
When the comparison is complete, the following appears in the dialog box:
Differences. Shows both drawings superimposed.
Drawing 1 and Drawing 2. Shows an image of both drawings that were compared.
After the comparison, select from the following:
Additions. Clears Drawing 2 from the Differences display.
Removals. Clears Drawing 1 from the Differences display.
Open Results
. Opens previously saved DrawCompare results.
Save Results
. Saves the DrawCompare results as a compared bitmap
file (*.Compare.BMP).
Close the dialog box.
To use the DrawCompare tool with detached drawings:
When you compare
a detached drawing, DrawCompare compares a bitmap of the detached drawing
to a bitmap of the same drawing with the models fully-loaded.
Click Tools, DrawCompare.
For Drawing 1, click Browse to locate a detached drawing.
Click Compare Detached Drawing 
or File, Compare
Detached Drawing.
The detached drawing opens and the models are fully-loaded for the comparison.