Reader or Acrobat loads instead of other application and displays unsupported file type error
When you run any program in Windows, Adobe Reader or Adobe Acrobat loads instead and displays the error message, "not a supported file type", on Microsoft Windows Vista.
An application or virus has corrupted the EXE extension in Windows, when Windows asked for a program to open EXE files with, Adobe Reader or Adobe Acrobat were at the top of the list of applications when you clicked OK. When this happens you associate Adobe Reader or Adobe Acrobat with the .exe extension which is typically reserved for application execution.
Note: This is an issue with a third party application replacing the EXE extension on Microsoft Windows Vista, and not an issue created by Adobe Reader, Adobe Acrobat or Adobe Inc. Adobe technical support does not provide support for third-party software and provides this information as a courtesy only.
Use the Windows registry editor to restore EXE class defaults.
Remove Adobe Reader or Adobe Acrobat from add/remove programs.
Click Start > type in appwiz.cpl in the search window and press enter.
Select Adobe Reader or Adobe Acrobat and click Uninstall. After installation if you are prompted to reboot - chose Restart Now.
Click Start > type in regedit into the search window and press enter.
Disclaimer: This procedure involves editing the Windows registry. Adobe does not provide support for editing the registry, which contains critical system and application information. Make sure to back up the registry before editing it. For more information about the registry, see the Windows documentation or contact Microsoft.
Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.exe.
Right click on OpenWithList and chose delete.
Right click on UserChoice and chose delete.
Reinstall Adobe Reader or Adobe Acrobat.
Adobe Technical support has tracked this issue down to two products that may cause this issue: the Intuit update manager for Quickbooks, and the Corel update manager for Wordperfect. For more information on these products contact Intuit Corporation or Corel Corporation respectively.