exception while Installing WP7.1?

Previously I installed WP7 RTW in my machine. Now, I need to install the latest version for windows phone 7.1 SDK in to my machine. So开发者_JAVA百科, when I try to install the windows phone SDK 7.1 I'm getting exception, it says, need to uninstall the "Visual Basic for windows phone developer tool-RTW".

thanks in advance.

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update to Visual Studios Service Pack 1 2010, that helped with my issues.