We have narrowed down everything there hardware wise, update wise, etc. It has to Windows SP2c disk. Strangely, if you take the same system, install 1.2, the the 1.5.1 patch, all is well.
Going from Windows XP Media Center Edition to XP Pro is a downgrade of the OS.
Installing the VT5 prerequisites seems to help some users, so I am providing a link below.
If you have already installed SpeedEDIT and received the error, please install this and then attempt to launch SpeedEDIT.
If you have had the vcredist error and uninstalled SpeedEDIT, install this new prerequisite from the link above and then install SpeedEDIT, but deselect the option to install the SpeedEDIT prerequisites.
Let me know if this helps,