Parallels build 4.0.3540 ( November 22, 2008 ) I'm running Vista installed on a bootcamp partition. When I start the VM I get the following error: System extension cannot be used The system extension "/Library/Filesystems/fusefs.fs/Support/fusefs.kext" was installed improperly and cannot be used. Please try reinstalling it, or contact the product's vendor for an update. Any ideas? Rgds, R.