If you have shell.dll missing from your computer, you may be experiencing a number of problems. The least of these will be an “illegal operation” dialog box that opens up when you try to view a web page or open your favorite program.
What causes shell.dll to go missing?
There can be many reasons for this file to disappear.
The least malicious of them may be that you accidentally deleted the file when you were cleaning out your registry. This is only one reason you should never try to clean your registry “by hand” (due to the massive potential for error, even many PC technicians won’t touch this job!).
The program may have disappeared during a bad install or uninstall of a program on your computer. This kind of error is simply caused by bad programming.
A bad install may overwrite the file with another (different) file that, unfortunately, has the same name. On the other hand, a program could have thought the file was one of its own and deleted it as part of the uninstall process.
The file may also have disappeared if a malicious program such as spyware or a Trojan horse damaged the registry. Unfortunately, the kinds of programs that remove malicious software, often do not fix the damage that bad software can make to the registry.
One thing you shouldn’t do to replace a missing shell.dll file.
There is one tempting thing you should definitely not do to replace shell.dll (or any other .dll file): You should not download a free replacement from a free download site! Why?
For one thing, you can never be sure that you are getting the most recently updated version. Another thing, many of these “free download” sites don’t do a very good job of checking the files that are uploaded to them. These kinds of sites can be rife with just the kinds of spyware, adware, and viruses that will cause .dll errors in the first place!
You should always go to the source when you need to replace a missing file. Shell.dll controls many of the API functions in Windows, so it’s best to re-download the file straight from Microsoft.
3 ways to protect yourself from missing .dll files in the future.
Always get the latest updates, patches, and service packs from Microsoft as they become available. Check for them once a week at the very least. You can even set your computer to automatically search for these updates in the “Windows Update” section of Control Panel.
Regularly scan your computer with anti-virus and anti-spyware programs. There are some good free programs available like AVG, Malwarebytes, and Spybot: Search and Destroy. Download these programs and use them!
Scan your computer for registry errors. Unfortunately, there are not any free registry cleaners worth recommending at this time (”freeware” versions will sometimes delete the wrong files!). Legitimate registry cleaners will however offer a free scan up-front so that you can see if you really need to purchase them in order to fix shell.dll errors.
