This is the tricky part. How you locate your bookmark file depends on which browser you are using.
Netscape:
If your browser is Netscape, your bookmark file is probably called:
C:\Program Files\Netscape\Users\default\bookmark.htm
Try this first. If this does not work, use the Windows Find Files or Folders tool to locate the bookmark.htm file.
Internet Explorer
If your browser is IE, you need to actually create a bookmark file by exporting your favorites into one file. Do this as follows:
Select File, Import and Export.
IE will display the welcome screen for the Import/Export wizard. Click Next.
Select Export Favorites and click Next.
Click Next again to select your whole favorites folder.
Choose Export to a File or Address.
Accept the default path, but change the file name to bookmark2.htm. The result: C:\PROGRAM FILES\NETSCAPE\COMMUNICATOR\..\Users\...\bookmark2.htm. Note that the path may differ between machines so be sure to write down or copy the entire file name (including the path).
Click Next.
Click Finish.