Since the installer of Diablo 3 unlocked on midnight launch, new issues of installing the game has been discovered. Here are solutions from Blizzard forum that might help. Most of them can be solved by common techniques, but some are harder to deal with. If you want more information on problems of the installation, you can check on Blizzard's thread with tips.
We have some major problems:
ATI 1.24 Catalyst graphics issueBlizzard has recently become aware that playing Diablo 3 with the latest Catalyst 12.4 drivers for ATI cards may cause some visual artifacts for specific hardware configurations. This issue affects users of ATI Radeon HD 2400, 2600, 2900, 3400, 3600 and 4500 graphics cards under Windows Vista and Windows 7. ATI Radeon HD 4600, 4700, 4800, 5000, 6000 and 7000 series products are unaffected, as is Windows XP.
Update: ATI has released a Catalyst 12.4a driver hotfix for the affected cards.
Digital download yet "Disc Ejected" errorIf it's asking for a disk then it means an entire data tome is missing from the download. I'd recommend restarting the downloader to see if you can pick that up.
When restarting the downloader, make sure to select the same download folder that you did before. It should have the Diablo 3 installer file inside it. Allow the downloader to completely finish. It will launch the installer on its own when it is done.
Similar to "An unexpected decryption error occurred", the error 108 can be caused by corrupted, damaged or incomplete installation files. This can often times be caused by closing the downloader early. Though the downloader may show 100%, please allow some time for it to fully complete.
You may be able to fix this by running the downloader and pointing it to the same saved location so that it may scan and download any missing files.
Unexpected decryption error occurredThis error message generally indicates that the installation files may be corrupted, damaged or incomplete. Please make sure your download has finished before attempting to install the game. Secondly, make sure the installation executable file is in the same folder as all your other D3 installation files. If the problem persists, you may need to delete all the files and restart the download.
Your installation folder should not have any files with the .Part extension. If it does, it indicates the downloader was closed prematurely. Restart the downloader in this case, selecting the same location the "Diablo-III-8370-enUS-Installer" folder is in, and it will check the existing files and download what's missing. It's important to let the downloader finish on its own. It will start the "Diablo 3 Setup.exe" file when it's done. It can take a while so please be patient.
During the Beta, several startup issues were resolved by setting the Diablo 3 tools to run in Compatibility Mode. At this time, Compatibility Mode for the retail tools is no longer needed. In fact, setting the tools to run in Compatibility Mode may cause other issues with the Blizzard Launcher. If you are having issues with the game and normal troubleshooting steps have not helped, please create a thread here or you can create a Support Ticket on your Battle.net Account Management page.
New Downloaders for English and German
Blizzard became aware of an issue affecting the previously available German and EU English versions of the digital install downloader for Diablo 3, which would not download all the necessary files. If you've pre-downloaded the digital version of the game in these languages before 10:00 AM CEST (9:00 AM GMT) on Saturday May 12, you must obtain the new downloaders to be able to install properly once the game is released on May 15.
1. Obtain the new Diablo 3 digital downloader using the links below
2. Point the download save at the same directory as before
The folder in question is your main game data folder. If you have the game downloaded to D:\Games\Diablo-III-8370-enGB-Installer, please point the download to D:\Games\. Do not use the automatically generated folder containing the installation files (i.e. do not use the directory D:\Games\Diablo-III-8370-enGB-Installer as this is the one created by the downloader).
3. If you chose the correct directory only around 65MB will need to be downloaded to fix your install, otherwise you'll re-download the entire 7.6GB
For more information or help with the installation, check out the Diablo 3 Pre-Sale Downloader Walkthrough or use the search on the Battle.net support site.
Whether you repair your previous install or download the entire game again, it's necessary to use this new downloader to install and play the game when it launches.
Nothing happens when running the D3 setup
If you try running the Diablo 3 Setup.exe file and nothing appears to be happening, check to see if the Windows Service for Secondary Logon is enabled. The game requires it and will not run if it's disabled.
To check, open Control Panel > Administrative Tools > Services and scroll down to the Secondary Logon service. Right click it and select properties. Make sure the Startup Type is NOT set to Disabled. Any other setting is ok.
This service being disabled may also cause the system to appear to hang during the "Updating Setup Files" portion when run.
Overlay programs crash Diablo 3
If you're encountering crashing when launching the game, you will be asked to check and see if you have any of the following third party programs running.
• EVGA Precision
• Airfoil by Rogue Amoeba
• MSI Afterburner
In some cases, simply updating the program can resolve the issue, but if it continues, please do not run these programs at all while launching Diablo 3. In almost all cases it has to do with an overlay that the 3rd party programs use that causes the crash.
Removing beta filesIf you participated in the Diablo 3 beta, please remove all Installation Files before attempting to install the retail client. You may remove the game files using the Uninstall Program features in Windows (Add/Remove programs if you are on Windows XP). After uninstalling the game, browse through your hard drive and ensure that the following folders have been deleted: C:\Program Files\Diablo 3 Beta
Or if you installed to another location, make sure the game folder is deleted.
If you guys are seeing a Tome error when installing then there's probably an issue with the downloaded files. These can be incomplete if the downloader wasn't able to finish.
As has been mentioned, launching the Diablo 3 downloader and directing it to the same folder as before will allow it to download the installer files again. Please make sure to leave the downloader alone as it works. When it has finished downloading the files to completion, it will launch the installer on its own. Closing it early can cause this issue to reoccur.