Help! I have reinstalled Vista OEM on the same machine, but now I am having problems installing software. It is not allowing me to install Office 07 - it says Office Source Engine has encountered an error. it is not allowing me to install SP1 - it says stub has stopped working. It is not allowing me to install virtual DVD drive - it says internal error. I have not added any new hardware. Although Vista did used to be installed on a different drive. I have totally removed that drive. And I have reformatted the current drive. I have even used a friends disc. This is the 4th time I have installed Vista now. It seems to be hit and miss what installs. I have used various sources as well, but all do the same. My copy of Vista has been validated and is activated.