在SQL SERVER 2008 R2下用Windows 身份認證的登錄名創建了一個訪問ORACLE數據庫的鏈接服務器xxxxx，測試成功，木有問題，但是其它登錄名使用該鏈接服務器時，報如下錯誤：
消息 7302，級別 16，狀態 1，第 1 行
Cannot create an instance of OLE DB provider "OraOLEDB.Oracle" for linked server "xxxxxx".
此時需要在“服務器對象”——>“鏈接服務器”——>“訪問接口”下，找到OraOLEDB.Oracle選項，單擊右鍵選擇屬性，然后在訪問接口選項下勾選“允許進程內”（Allow inprocess）。即可解決上面問題，有時候，可能需要重新新建此鏈接服務器。
老外給出了一個解決這個問題的步驟，相當詳細嚴謹，幾乎面面俱到。可以作為參考學習的好資料：
Ran into this issue where the linked server would work for users who were local admins on the server, but not for anyone else. After many hours of messing around, I managed to fix the problem using the following steps:
1：Run “dcomcnfg.exe”. Navigate to “Component Services -> Computers -> My Computer -> DCOM Config”.
2：Open the properties page of “MSDAINITIALIZE”.
3：Copy the “Application ID” on the properties page.
4：Close out of “dcomcnfg”.
5：Run “regedit”. Navigate to “HKEY_CLASSES_ROOT\AppID\{???}” with the ??? representing the application ID you copied in step #3.
6：Right click the “{???}” folder and select “Permissions”
7：Add the local administrators group to the permissions, grant them full control.
8：Close out of “regedit”.
9：Reboot the server.
10：Run “dcomconfig”. Navigate to “Component Services -> Computers -> My Computer -> DCOM Config”.
11：Open the properties page of “MSDAINITIALIZE”.
12：On the “Security” tab, select “Customize” under “Launch and Activation Permissions”, then click the “Edit” button.
13：Add “Authenticated Users” and grant them all 4 launch and activation permissions.
14：Close out of “dcomcnfg”.
15：Find the Oracle install root directory. “E:\Oracle” in my case.
16：Edit the security properties of the Oracle root directory. Add “Authenticated Users” and grant them “Read & Execute”, “List folder contents” and “Read” permissions. Apply the new permissions.
17：Click the “Advanced Permissions” button, then click “Change Permissions”. Select “Replace all child object permissions with inheritable permissions from this object”. Apply the new permissions.
18：Find the “OraOLEDB.Oracle” provider in SQL Server. Make sure the “Allow Inprocess” parameter is checked.
19：Reboot the server.