OOPS!!
Sorry to post spam: but it didn’t work as expected.
Movie Studio would open the file, and I began to edit and proceed; however, the video is corrupt! After a short time, the playback is slewed and full of artifacts. The preview is totally messed up.
I tried to save a short clip, and the output is also messed up.
So this turned out not to work!
I have cured my problem with Media Converter 8: I was finally able (after many attempts with many different converters) to convert the file to an mp4 and Movie Studio will finally import this file.
This was maddening! Windows Media Player would play the original recording (a screen recording, in H264, saved as AVI), but I could not convert the file until a dozen attempts! Finally I found the right settings in Media Converter 8 to create an mp4 that Movie Studio has now opened and is working with fine.
So again, sorry to post spam, but at this point I have uninstalled that codec, and after conversion I am working fine. I will be sure to record differently next time!