Unfortunately, you haven't given us nearly enough information to help you.
What type of camcorder is your video coming from? Are you using Premiere Elements' Get Media tool to get the video from the camcorder into your computer?
When you started your PRemiere Elements project, which project settings did you select?
What operating system are you using?
How much free, freshly defragmented space is on your C drive? Are you editing your video on your C drive or on a second or external drive? If you are editing to another drive, have you ensured that the drive is formatted NTFS and not FAT32, as they come from the factory?
my video is coming from a mini dv
camcorder and am using premiere elements 8. my setings are for the DV standard 48hkz. my operating system is windows 7. only 13 GB of memory is left
only 13 GB of memory is left
If that is only 13GB of HDD space left, then it is very likely at least part of the problem. This will be especially true if your Windows Virtual Memory (Page File) is dynamically managed (the default), as you will have even less space, than you are seeing, with the computer at idle.
One other consideration is that as a HDD nears 70% of capacity, it begins slowing down, and the slowing is exponential, as one gets closer to 100% capacity. Near 100%, the likelihood of failure goes up too.
With miniDV tape Capture, the files will be DV-AVI, the best that you can get, and they will occupy ~ 13GB per hour of tape.
I would do a major cleaning of the HDD.
I agree with Bill. Premiere Elements has a problem running on computers with less than 20 gigs of free, defragmented space on the C drive -- especially if you are using that same drive to run your programs and to store your project and media files.
You'll do well to clear off another 15 gigabytes of space and defragment your drive. You'll do even better to add a second hard drive or even an external drive as your media and project file area.
Also, if you haven't applied the patch for Premiere Elements 8, then I would recommend you to apply it. You may get it from "http://www.adobe.com/support/downloads/thankyou.jsp?ftpID=4653&fileID=4342"