DLLs are little executable files that contain data that multiple programs can use at once. This saves space on your hard drive because not every program needs to take up space with the same code. Generally, DLLs are very helpful when it comes to the functionality of your PC. However, they can also be used for evil. Gasp!

Some types of spyware use DLLs to do their dirty work, infecting your PC with bad stuff. And with DLLs, you can’t just delete them. They must be deleted and disabled in your system before they are gone for good. So how do we do that?

Safety First

You may have pinpointed the bad DLL that is messing up your system. However, you should still take precautionary measures before disabling and deleting them
Precautionary measures equal: backing up your files (like you’re supposed to do regularly anyway) and creating a System Restore Point. In order to create a point that you can return your system to in case of catastrophe:

1. Click on your Start button and go to All Programs.
2. Open Accessories and then System Tools.
3. Click on System Restore and follow the onscreen instructions.

Step 1: Finding a DLL

The first step to disabling a DLL is to do a search for it on your PC and find the exact path of the DLL.

1. Go to your Start menu and click on Search. In Windows Vista and Windows 7, you can just search from the Start-Menu's Search Field

2. Click on All Files and Folders and then type the name of the DLL you need to delete.

3. Write down the path to the DLL, typically it’s usually something like C:\Windows\System32 but there are other DLLs that follow different paths.

Step 2: Disabling a DLL

1. Click Start and then Run to open your command prompt window.

2. Type CMD in the Open blank and click OK.

3. When it opens, it will say the Drive Name, followed by “Users” (in Windows Vista/7) and then the user's name or "Windows" (In Windows XP).  It will look like this: C:\Users\Joe> or C:\WINDOWS>

4. Type "cd/", which will change the prompt to the base directory, it will leave an open prompt with just the Drive name:  C:\>

5. Type "cd" again, then a space, then /.  After that, enter the full path to the DLL file. This is the path that you wrote down in step 1.  Remember to separate subfolders in a directory with the \ symbol.

6. At this point, you can type DIR to have the command prompt show you a list of all the files in that directory.  It's a good way to verify that the DLL you're looking for is inside.

7. Once you’re in the directory of the DLL you want to disable, type regsvr32 /u [DLL_NAME] and hit return.  This tells the computer to uninstall the running service of the DLL, thus disabling it.

8. If it was successful, you will see a confirmation message.

Step 3: Deleting the DLL

When the DLL is successfully disabled, you can then go ahead and delete it.  That's a simple matter.  Just find it in your computer (in the directory you wrote down) and delete it, putting it in the recycle bin.  At this point, it's a good idea to keep in mind safety.  Even with a system restore point on hand, it's not difficult to re-enable a DLL, so you can leave it in the Recycle Bin for some time, testing your computer to make sure it's behaving correctly.

Undoing what you've done

As long as the DLL is in the Recycle Bin, you can return it to the folder that it came from.  Just find it in the Recycle Bin and click:  "Restore Selected." Once it's back in place; just re-enable it.

Re-enable the DLL you've disabled by going to the command prompt and typing cd/ to go to the base prompt.  Then type “regsvr32″ without the /u key, then the DLL name.  It would look like this “regsvr32 [DLL_NAME]“ This will reactivate the DLL and everything should be back the way it was.