Cannot Run .exe files ?

What causes the program to run ("execute") when you double click the file name in My Computer or put it in the Run dialog box? Briefly put, it is an entry in the Windows Registry that does this.

For many, many different file extensions for files -- such as .doc for Word documents, or .txt for ASCII text files -- there is a location in the Registry that specifies how Windows handles such files. For .doc files it specifies, usually, that the Microsoft Word program (if present on the computer), or the Windows Accessory Wordpad if MS Word is not present, will be used to open up the document file so you can read and edit it. For .exe files, it specifies the "Open" action to be that which causes the program to run.

There are a number of viruses, trojans, and worms that mess up the Registry data for running executable (.exe) files, so this can cause nothing to seem to happen when you double click an .exe file name in My Computer or try to execute one by putting the name in the Run dialog box off the Start Menu.

If the virus/trojan/worm has been partially removed from your computer, then you might get a Windows error message such as "Cannot find program.exe". The reason the various types of malware modify the .exe file Registry key is to ensure that when you try to run any executable program, the malware program runs instead.

Data files for modifying the Windows Registry have the file extension .reg Various authors have come up with .reg (Registry) files to restore the proper contents of the .exe entry. If the .exe file association entry in the Registry has been modified, then you cannot even run the Registry Editor, Regedit.exe in order to try and correct the problem.

Somewhat often, you can rename the Registry Editor program to another type of executable by changing its name from Regedit.exe to Regedit.com and then you can edit the Registry. But edit it to what? If the Registry entry for .reg files has not been maliciously modified, it is easier to download the appropriate .reg file for your version of Windows and then double click the file name in order to fix the .exe entry.

For Windows XP, you can find one this way: right click this registry file, click save target as on popup menu for download it. After that, double click that file and click OK. Restart your Windows, and finish. You can run the .exe files as before now!

You must do the same trick above for Windows 9x/ME, but the corresponding registry fix is here.