Microsoft.Windows.Networking.RtcDll

i am getting these error whenever i try to run a pc-to-phone software "Dial2day".
Initially when i click the exe shortcut, i get error saying;
"This application has failed to start because the application configuration is incorrect.

Reinstalling the application may fix this problem."
i looked at the EventViewer and found these errors;
------------Error No. 1----------
Event Type: Error
Event Source: SideBySide
Event Category: None
Event ID: 59
Date: 31/08/2009
Time: 5:32:26 PM
User: N/A
Computer: PERSONAL-435CEF
Description:
Generate Activation Context failed for C:\Program Files\Home\Dial2day\Dial2Day.exe. Reference

error message: The operation completed successfully.
.
------------Error No. 2---------
Event Type: Error
Event Source: SideBySide
Event Category: None
Event ID: 59
Date: 31/08/2009
Time: 5:32:26 PM
User: N/A
Computer: PERSONAL-435CEF
Description:
Resolve Partial Assembly failed for Microsoft.Windows.Networking.RtcDll. Reference error

message: The referenced assembly is not installed on your system.
.
------------Error No. 3----------
Event Type: Error
Event Source: SideBySide
Event Category: None
Event ID: 32
Date: 31/08/2009
Time: 5:32:26 PM
User: N/A
Computer: PERSONAL-435CEF
Description:
Dependent Assembly Microsoft.Windows.Networking.RtcDll could not be found and Last Error was

The referenced assembly is not installed on your system.

Please if someone help me get rid of it. first-of-all whats is this side-by-side Source and

2nd form where will i get this missing Assembly.

i am using WinXP SP3