Solved Slow Playback After Rendering

I am very low on the pole so I won't pretend to know the tech terms can barely peck to type but I enjoy playing in my Vegas Movie Studio Platinum HD 11 and have done a few projects. I have just tried to do a more complicated project with multiple videos running in the same window by splitting the window into reducing the size of the file playing to reveal the clip beneath playing also. I got bold and had the window playing four clips at once with a sound track below looked good when I previewed it but once rendered it played lousy on my pc. The only thing I knew to do was create more space on my operating drive by exporting all of the other folders from the various things that I can move and make space and hopefully that will be the simplest solution a lack of memory on my c drive. Was trying to play it back on real player or windows media player

Hi Choo Choo

Something has gone wrong with your video during the rendering process or it has something to do with your project settings.
It does not matter how many different videos are playing at the same time, once the video has been rendered. To the computer, this is exactly the same as one video playing.
Problems could be caused by the videos you used having different Frame Rates - this could definitely make the videos look glitchy.
If all the videos you used (lets say 4x videos), were all located on the same Hard Drive, then all 4x videos have to be read at the same time during rendering. On top of that, if the Video is being Outputted/Saved to the same Hard Drive that the original videos are located on, that means your Hard Drive is having to Read 4x times and Write 1x times - all at the same time !
If this hard drive is relatively full, slow and badly fragmented - then this is probably what caused the render to not work properly.
A better solution is if you have at least 2x Hard Drives.
One has all your Source Media and is in Read Mode only.
Number two Drive would be used for Writing/Outputting your Video files.