Nothing is more frustrating than an error code that doesn't communicate much information. Seeing "Adobe failed to load core DLL" when you try to open Adobe Reader doesn't tell you why the program can't load or how to fix it. However, you can fix this problem and regain the use of Adobe Reader.
Adobe has traced the "Adobe failed to load core DLL" error to three causes. Adobe Reader might need to be repaired, malware may be interfering or the program may be corrupt. Of course, you want to be able to use Adobe Reader again, but it's especially important to fix a malware problem if that is the cause. The rootkit that interferes with Adobe Reader could be stealing your personal information. Attempt these repair solutions in the order they are presented.
Repair Adobe Reader
The simplest fix is to repair Adobe Reader. Right-click the Windows button and click "Control Panel." Click "Programs" and "Programs and Features." Click Adobe Reader in the list of programs. Click the "Change" button. In the Setup dialog box, select the "Repair Installation Errors in the Program" radio button. Click "Next," Adobe Reader repairs itself.
Malware in the form of a rootkit could have been installed on your computer without your knowledge. Adobe recommends using the TDSSKiller program from Kaspersky to fix the rootkit that causes the "Adobe failed to load core DLL" error. Install TDSSKiller and open the program. Click "Start Scan." When the scan is finished, select "Cure" next to any malware that TDSSKiller found. Click "Continue," then click "Reboot Computer" to finish removing the malware.
Reinstall Adobe Reader
The last resort is to start over with a fresh copy of Adobe Reader. Right-click the Windows button and click "Control Panel." Click "Programs," then "Programs and Features." Click Adobe Reader in the list of programs, and click the "Uninstall" button. Adobe Reader is uninstalled from your computer. Download the latest version of Adobe Reader and install it.