Hi everyone, I've been using Windows 7 Beta (6.1.7000) for a while and I haven't had any problems getting programs to install and run, until now. I recently tried to install Autodesk Inventor 2010 and the installation failed 2/3 of the way through with this error: The error is fatal so the installation rolls back after this occours. I checked Microsoft support with no luck, or it was just too confusing. I hope someone here can give me a hand. Reinstalling Windows 7 will almost surely fix the problem, but I really want to avoid having to. Some info: The installation works fine on Windows Vista Home Premium 32-bit on the same computer. I always disable all firewall and antivirus programs before trying to install. The installer is using Windows Installer, "msiexec.exe" runs while the installer is working. Using Windows 7 Beta build 700 on an AMD Athlon 64 X2 TK-55, x86 based. 1 GB of RAM. I tried installing after backing up to a restore point that was a while before this problem and it the same error occurred. Plenty of HD space for the program. I had this same error message while trying to install VMware Workstation 6 later. Thank you for your time!