error after upgrade from version 5.16.3 to version 5.18.1

Hello,

my name is Christian Stengg, I am a teacher from Austria. I have been 
using wxmaxima (with Windows XP) with great benefit for my daily work 
since about two years. Today I wanted to upgrade from version 5.16.3 to 
version 5.18.1. So I uninstalled the old version using the uninstaller 
and installed the new version. When I started wxmixa, I got an error 
message (see below) and could not use maxima any more. The message 
refers to the qdraw macro package. I remember that I sometime configured 
that this package is loaded automatically at program start (but I don't 
remember how I achieved this). I found out that after the uninstall 
there were still two folders (one for the new and one for the old 
version) in my programs folder. I uninstalled the new version, deleted 
these folders and reinstalled the new version, but the problem remained. 
I uninstalled the new version, deleted the corresponding folder, 
reinstalled the old version and had the same problem in the old version. 
The error message occurs in wxmaxima and in command line maxima.
I don't understand how maxima remembers this problem beyond uninstall 
and reinstall and I have no idea how I could solve the problem. I would 
be very grateful if someone could help me because I need maxima for my 
daily work.
Thankyou in advance,

Christian Stengg

Error message:

Maxima 5.18.1 http://maxima.sourceforge.net
Using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (aka GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
Could not find `qdraw' using paths in file_search_maxima,file_search_lisp.
-- an error. To debug this try debugmode(true);
Maxima encountered a Lisp error:
Error in PROGN [or a callee]: The tag MACSYMA-QUIT is undefined.
Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
Error in MACSYMA-TOP-LEVEL [or a callee]: The tag RETURN-FROM-DEBUGGER 
is undefined.
Fast links are on: do (use-fast-links nil) for debugging
Broken at CONDITIONS::CLCS-UNIVERSAL-ERROR-HANDLER. Type :H for Help.
1 (Continue) Maxima top-level
2 (Abort) Return to top level.
dbl:MAXIMA>>