Turn off multi processing.
Purge all memory.
Show us a screenshot of your preferences showing the memory problem.
Run a system test on your memory. You may have a faulty module.
Tell us about your system details and the exact version of AE.
From the little we know it looks like you have a memory problem somewhere but we don't know anything about your system, your OS, or the build number of CS5.
Here's my system configuration -
Processor -Intel core i5- 2310
Ram -10 GB
System - 64 bit
I am using Adobe Master Collection CS5.
Multiprocessing is turned off and i have tried purge all memory too.
I really don't know how these memory settings get changed. After installing new window and after effetcs It worked well and settings were different too like- Ram reserved for other applications was - 3GB
Thanks for the link . I'll try this.
I have even updated it but still its not working ...