WINDOW2008 64-bit system without Office component problem analysis and resolution

The server is a Windows server2008 64-bit system,
My system needs to use the Microsoft.Office.Interop.Excel component.
Error encountered while uploading Excel document: Failed to retrieve component of CLSID {00024500-0000-0000-c000-000000000046} in COM class factory.
Online circulation of countless solutions:

Normal version steps
1. In Start, run, enter Dcomcnfg.exe to start the Component Services
2. Double-click "Computer", "Component Services", "My Computer", "DCOM Configuration"
3. In the DCOM configuration, locate the Microsoft Excel application, right-click on it, and then click Properties to pop up the Microsoft Excel Application Properties dialog box
4. Click on the "Logo" tab and select "Interactive User"
5. Click on the "Security" tab, click "Customize" on "Launch and activation Rights", then click on the corresponding "edit" button to add a "NETWORK SERVICE" user in the "Security" dialog box (note to select the computer name), and give it "local launch" and "Local activation" Permissions
6. Remain the "Security" tab, click "Customize" on "Access", then click "Edit" and add a "NETWORK SERVICE" user to the "Security" dialog box that appears, then give "Local access" permission.

The problem is on a 64-bit version of the machine, because the item "Microsoft Excel application" cannot be found after opening dcomcnfg, because DCOMCNFG is a 32 configuration and is fully supported under 64-bit systems, so it is just guacai.
so I looked up the way to open the 32-bit DCOMCNFG .：
1. Run: mmc-32
2. Open "File"-"Add or remove Snap-in"-Select Component Services-click Add-OK.
3. Microsoft Excel application can be found in the DCOM component.

So the top of the way to configure the completion, run the site, the same error.
Check again and the content is not finished setting.
Check the settings of the IIS7, and finally determine that you also need to set the identity of the application pool, the AppPool of this site to be set to LocalSystem or NetworkService, problem resolution.

WINDOW2008 64-bit system without Office component problem analysis and resolution