101. Customize the HTML error pages

Some times, when you type a webpage address you might see an error page. A very common
error page that we come across is “Page not found” page. These error messages do not come
from any server. They are all stored in a DLL file in our system itself. The name of the dll file
is SHDOCLC.DLL file. If you don’t trust me then copy the following address and paste it in
your IE address bar and see for yourself.

res://c:\\Windows\\System32\\SHDOCLC.DLL/servbusy.htm

Now replace servbusy.htm with other html files given below .

http_400.htm, http_404.htm, http_406.htm, http_410.htm, http_500.htm, http_501.htm,
http_gen.htm, servbusy.htm, syntax.htm, navcancl.htm, offcancl.htm, policyerror.htm,
policylooking.htm, policynone.htm, policysyntaxerror.htm, privacypolicy.dlg, preview.dlg,
printerr.htm, printnf.htm, printnof.htm, printunk.htm, wcee.htm, ietext.bmp, ietext256.bmp,
world.bmp, world256.gif, ie.gif, ie256.gif, orgfav.dlg, about.dlg, analyze.dlg, bidifind.dlg,
docppg.ppg, error.dlg, find.dlg, findic.dlg, ieerror.dlg, imageppg.ppg, orgfav.dlg, and
pstemplate.dlg (Do you trust me now???)

If you need to customize these messages, write an error message and store it somewhere on
your hard disk. We can replace all these HTML error pages with our own. Navigate to
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InternetExplorer\AboutURLs. You
can change entries associated with various keys and provide complete path name to your own
custom html file.