Hi,
There are lots of programs that might check/modify just created files on windows, on-access virus scanners are just the most common.
Typical other candidate are for example: Image Previewers that create thumbnails, Tortoise SVN directory scanners, some Adobe Acrobat Quick Start tools
and so on.
The error message Henri picked shows that another program probably injects a Debug DLL into the running process, which makes it fail, this is typical of Virus scanners and anti-cheat tools:
"Someone took over my signal/exception handler (post messagehandling) "
If you know how to use Sysinternals ProcessExplorer, you can find out who is doing that:
http://technet.microsoft.com/de-de/sysi ... 96653.aspxBasically, start up Cool Viewer, try to upload a picture, than switch to ProcessExplorer and select the CoolVLViewer.exe process from the upper tab.
Now select 'View->Show Lower Pane', switch it to show the loaded DLLs and look at the provided list in the lower part of the window.
If you see any DLL from your virus scanner or similar stuff listed there, you have something hooking into the viewer.
If in doubt, post the list of loaded DLLs for the process.