Martin installed the Windows 7 public beta in a Virtual PC. All was well until he installed the VM Additions. I downloaded the Windows 7 beta last night and installed it in a Virtual PC this morning. I used the Virtual PC settings for Vista, which includes 512MB of RAM available to the Virtual PC.It worked, albeit slowly, until I installed the VM Additions. On reboot, one of the drivers from the VM Additions threw a fault. Allowing system recovery to revert to the last restore point got the system booting again.[ Can your PC run Windows 7? Find out with the Windows 7 compatibility checker in InfoWorld’s free Windows Sentinel utility? ] An Internet search found only one other report of this, here. I hope that Microsoft can come up with a fixed VM Additions distribution fairly quickly. Meanwhile, don’t install the VM Additions into Windows 7.My understanding is that I’m not seeing the full glory of the enhanced Aero look of Windows 7 when I run it in a Virtual PC, but at least I can use this installation to regression test my own software and look at the current build’s sensitivity to additional RAM. When I get a new desktop built, I’ll reserve a partition for Windows 7 test installations, and then I’ll be able to tell something about the runtime speed of this build.Obligatory disclaimer: Microsoft operating system betas are not intended for benchmarking. Historically, runtime speeds have changed considerably from build to build as the developers tweaked the system in response to user feedback and internal test results, and not always in the direction of faster: sometimes speed has to be sacrificed for safety. So even if I can test this build, I won’t be able to project the performance of the final release build. Software Development