I have been using Visual C# Express Edition productively for a couple of months now - very impressed with the stability and only having to deal with a few minor quirks.
Today unfortunately I am encountering issues with the Toolbox. Upon starting up the IDE today and loading my ongoing project, I found that several Toolbox categories had gone missing. For example the "Common Controls" category.
So, I decided to try the Reset Toolbox option.
When I did this (and it's happened twice now) I received the following error message (a dialog box):
Microsoft Visual C# 2005 Express Edition
Microsoft Visual C# has encountered a problem and needs to close.
if you had files open that contained unsaved changes, these changes might be lost.
[x] Restart Microsoft Visual C# 2005 Express Edition
Send an error report to Microsoft
A report has been created that includes more information about the causes of this error. Submitting this report helps Microsoft improve Microsoft Visual C#.
...
[Send Error Report] [Don't Send]
After restarting the IDE, I am left with a Toolbox that contains only a General category and 2 controls (pointer & button). I am looking at having to do a reinstall I guess...
Can anybody suggest an alternate solution
The only thing I can think of that might have precipitated this is that I did try (yesterday) to re-arrange some of the categories in the Toolbox so that the ones I used most commonly would appear nearer to the top of the list.
Visual C# Express Edition: Toolbox Components Disappeared / Reset Doesn't Work
Christian Bogino
Wow, sounds bad. I have a problem with toolbox icons, they mutating from time to time (if you interested look here http://lab.msdn.microsoft.com/ProductFeedback/viewfeedback.aspx feedbackid=57da7607-c27c-44c3-a04f-768d7cc54719).
In your case I think you should report to MS about bug, here is the link: http://lab.msdn.microsoft.com/productfeedback/default.aspx
gbarendt
Thanks again Sergey
for the useful info which led to a resolution to the problem. You are awesome! 
David Guyer MS
Wait before uninstall whole stuff! I just get an idea
- toolbox have a cache, you can find about it in first link I provide. May be you try delete cache first
Also you can try Import/Export settings, sometimes it helps.
Chrutil
Update - well I've just finished doing a Repair/Reinstall from the Add/Remove Programs applet in Control Panel. This does not resolve the problem. When I right-click in the Toolbox tray and do a "Reset Toolbox", I still get the same VC# 2005 Express Edition crash.
Thanks Sergey for your comments. I will probably report as a bug as you suggested. And this time I will do a full uninstall / reinstall.