can't compile hello.c with Clang in win7

Hi all !
i am a newcomer to llvm.
i had built llvm+clang(r170994) successfully with VS2008 in win7 today.
the following commands ran well:

clang -c hello.c -emit-llvm -o hello.bc
lli hello.bc

but when ran :

clang hello.c -o hello.exe

an error occurred:

Assertion failed: !getRelaxAll() && “Did not expect a MCInstFragment in RelaxAll mode”, file …\llvm\lib\MC\MCAssembler.cpp, line 867
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application’s support team for more information.
clang: error: clang frontend command failed with exit code 3 (use -v to see invocation)

anyone help me ?

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