I re-downloaded the installation package but still the same. It happens in the installation wizard.. The installation progress bar stays empty and the error appears.
this is the error in the logfile:
C:\DOCUME~1\test\LOCALS~1\Temp\Silverlight Tools RTW\TMP1B5.tmp: Verifying signature...
[10/3/2008, 9:19:28] (IronSpigot::FileSignatureT<class IronSpigot::WindowsCryptAPI>::Verify) C:\DOCUME~1\test\LOCALS~1\Temp\Silverlight Tools RTW\TMP1B5.tmp - Signature verification for file C:\DOCUME~1\test\LOCALS~1\Temp\Silverlight Tools RTW\TMP1B5.tmp failed with error 0x800b0100 (No signature was present in the subject.)
[10/3/2008, 9:19:28] C:\DOCUME~1\test\LOCALS~1\Temp\Silverlight Tools RTW\TMP1B5.tmp Signature could not be verified
[10/3/2008, 9:19:28] (IronSpigot::FileAuthenticity::Verify) Signature verification failed. Trying to verify hash ...
[10/3/2008, 9:19:28] (IronSpigot::FileAuthenticity::Verify) Hash verification failed. HRESULT = 0x80091007