For a generic guide on using a custom diff tool in TFS from My Eclipse:http://msdn.microsoft.com/en-us/library/gg475930.aspx#AssociateDifferenceTool
Combine this information with the guide provided on Beyond Compare's website: http://www.scootersoftware.com/support.php?c=kb_vcs.php
And you have the answer.
The steps I followed are (assuming you have downloaded and installed Beyond Compare, TFS, and My Eclipse):
- Open My Eclipse
- Navigate the menu: Window > Preferences
- Navigate the preferences screen: Team > Team Foundation Server > Compare Tools > Add
- Type in as shown

the full command is: "C:\Program Files\Beyond Compare 3\bcomp.exe" %1 %2 /title1=%6 /title2=%7
- Navigate the preferences screen: Team > Team Foundation Server > Merge Tools > Add
- Type in as shown

the full command is:"C:\Program Files\Beyond Compare 3\bcomp.exe" %1 %2 %3 %4 /title1=%6 /title2=%7 /title3=%8 /title4=%9
- Enjoy

That's it. Later I will tell you when you might actually want to do a file comparassons and why you might want to use Beyond Comare rather than the default compare tools of your IDE.
