2 things Al,
If you just want to play your video as video using Deskscapes then it will have to be a WMV format
which can be a large file size depending on length of the video, trim the video down in size to stay
under 150 MB's. WMV file will use 2 to 3 times the CPU usage than a AVI file.
If you actually want to make it into a dream file format then you want to do it as a AVI file. AVI will
be a much lower file size and cpu usage . Now try your video at full length and if still over the 150 mb size
then again you will have to trim it down,
You can use any video editing program to trim the video down in length if needed.
TRY This Free Converter ( I use it sometimes ) http://www.converterlite.com/
this converter will probably keep your video at 150 or less as an AVI file, try it and see.
Looping is another story but if it's just for you no biggie.
If all that fails just send it to me and i'll make it for you , LOL
I actually use up to 5 different converters depending on special needs
like Quality , maintaining looping etc.
Stardock Community Assistant