Does this happen for all output types or just for one format or set of output settings?
Rendering audio as well?
Yes it happens too all outputs
Yes including projects with audio. i have tried two completely two diff projects, one with audio and one without and they both end up the same. The file is rendered to the specified path which i have directed to a seperate hard disk. The file contains most data when looking at size of file but cant be played because its seen as corrupt or broken. Of course AE was hanging at the end of the render.
With only 4 GB RAM, you shouldn't be using multiprocessing. If it's on, turn it off. If you're using Open GL to accelerate rendering, turn that off too: it rarely helps, and often hurts. Your problem might be solved that easily.
But since you're on AE 9, it the footage you use could also be the problem. Most commonly it would be footage from XDCams, HDV cameras and DSLRs. AE 10 solved the problem, but that won't help you right now. However, a reply I used to give all the time on the Creative COW may still still apply:
Dave's Stock Answer #1:
If the footage you imported into AE is any kind of the following -- footage in an HDV acquisition codec, MPEG1, MPEG2, AVCHD, mp4, mts, m2t, H.261 or H.264 -- you need to convert it to a different codec.
These kinds of footage use temporal, or interframe compression. They have keyframes at regular intervals, containing complete frame information. However, the frames in between do NOT have complete information. Interframe codecs toss out duplicated information.
In order to maintain peak rendering efficiency, AE needs complete information for each and every frame. But because these kinds of footage contain only partial information, AE freaks out, resulting in a wide variety of problems.
I'm a Mac guy, so I like to convert to Quicktime movies in the Animation or PNG codecs; both are lossless. I'll use Apple's Compressor, Adobe Media Encoder or Quicktime Pro to do it.
Thank you so much