Access Denied on Applicaton Blocks

Why do I get this error when using the Microsoft Data Access Application Blocks? This only started happening AFTER I installed Windows XP Professional.

Thanks

Code:

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Server Error in '/Reviewer' Application.
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Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Access is denied: 'Microsoft.ApplicationBlocks.Data'.

Source Error:


Line 196:        <add assembly="System.EnterpriseServices, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
Line 197:        <add assembly="System.Web.Mobile, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
Line 198:        <add assembly="*" />
Line 199:      </assemblies>
Line 200:    </compilation>
 

Source File: c:\winnt\microsoft.net\framework\v1.1.4322\Config\machine.config    Line: 198

Assembly Load Trace: The following information can be helpful to determine why the assembly 'Microsoft.ApplicationBlocks.Data' could not be loaded.


=== Pre-bind state information ===
LOG: DisplayName = Microsoft.ApplicationBlocks.Data
 (Partial)
LOG: Appbase = file:///c:/inetpub/wwwroot/Reviewer
LOG: Initial PrivatePath = bin
Calling assembly : (Unknown).
===

LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Post-policy reference: Microsoft.ApplicationBlocks.Data
LOG: Attempting download of new URL file:///C:/WINNT/Microsoft.NET/Framework/v1.1.4322/Temporary ASP.NET Files/reviewer/1f814d9a/d5af3947/Microsoft.ApplicationBlocks.Data.DLL.
LOG: Attempting download of new URL file:///C:/WINNT/Microsoft.NET/Framework/v1.1.4322/Temporary ASP.NET Files/reviewer/1f814d9a/d5af3947/Microsoft.ApplicationBlocks.Data/Microsoft.ApplicationBlocks.Data.DLL.
LOG: Attempting download of new URL file:///c:/inetpub/wwwroot/Reviewer/bin/Microsoft.ApplicationBlocks.Data.DLL.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Post-policy reference: Microsoft.ApplicationBlocks.Data, Version=1.0.1265.21626, Culture=neutral, PublicKeyToken=null

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