Buffer size stops recording process

[grateful]

Help Anybody!

During a pro tools session it will stop in the middle of recording with a pop up saying that the cpu has other tasks that are interfering with the program. It asks to reduce the buffer size. I reduce it from 1024 to 512. A while later it says the same thing whle stopping recording saying to increase the buffer size. I increase from 512 to 1024. There are no other programs running and the pop ups go back and forth reducing then increasing buffer size. What do I do?
I have an Mbox, pc with 6.9 running.
Thanks ,
Grateful

[spkguitar]

Please carefully read through the General Troubleshooting thread and try the suggestions there. Buffer size errors can be caused by a number of common issues and Digi has put together that list to eliminate configuration and compatibility problems. Please don't forget the part at the end about posting system information.