Hi,
- How you tried installing the file from dll directory?
Follow the steps mentioned below and check if it helps.
Method 1: System File Checker (SFC)
SFC tool scans system files and replaces incorrect versions of the system files by using the correct versions.
To run the System File Checker tool, follow these steps:
a) Click Start, and then type cmd in the Start Search box.
b) Right-click cmd in the Programs list, and then click Run as administrator.
If you are prompted for an administrator password or confirmation, type your password or click Continue
c) At the command prompt, the following line, and then press ENTER:
sfc /scannow
How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7?**http://support.microsoft.com/kb/929833**
Method 2: Deleting the Battle.net folder along with everything in it should fix the issue because it will force the launcher to extract/download those files again. But if it keeps happening your antivirus may be deleting that file.
C:\ProgramData\Battle.net\Client\Blizzard Launcher.BUILD\QtWebKit4.dll This is the path to delete battlenet folder.
Method 3: Clean Boot Mode
Try installing the game in clean boot mode so, I would suggest you to keep the computer in clean boot mode and check if the issue still persists. A clean boot helps to verify if any third party application services or startup item is causing this issue.
Try installing the updates in the clean boot mode and check if the issue still persists.
You may refer the following KB article to put the computer in clean boot:
http://support.microsoft.com/kb/929135
Note: After the trouble shooting steps please refer to clean boot link to put the computer back to normal start up mode.
Hope this information helps.