Never has tweaking, adjusting, keeping it clean, been so important than when doing video editing.
The link below is well worth reading..
http://videoguys.com/Guide/E/Videoguys+System+recommendations+for+Video+Editing/0x4aebb06ba071d2b6a2cd784ce243a6c6.aspx
Personally, if you are serious about video editing, you really need to consider good hardware, and clean operating system.
I can't recall how many times clients try and use a 6 year old system for newer advanced software..
For those that must use a home PC for more than video editing let me make a suggestion...
1. Try to have at least 2 hard drives in the system.
2. If you can, install a much larger hard drive, and purchase or find one of many PARTITION tools allowing you to BOOT from different partitions.
Reinstall the operating system on another partition, getting all of the latest drives and such from the vendor and microsoft.
Tweak the crap out of this installation..
turn off windows search,
disable system restore,
read up on FSUTIL and choose accordingly
http://technet.microsoft.com/en-us/library/cc785435(WS.10).aspx
SATA drive makers often release new firmware for the drives to address issues,, check that out...
The goal is to Have the operating system running as perfectly as possible prior to ever installing something as complex as PD..
I would also strongly recommend that you have somthing like REVOINSTALLER running during the installation process... This will allow you to TRACK the entire installation and REVO will accurately and be able to FULLY uninstall the application. HINT - HINT, including many software packages that can detect multiple trial period installations. (Used for test purposes only)
Moving the PAGE file to a second DISK, recording video from another disk.. (the more the better)
KILLING unused Services is a good way to increase performance, and limit the number of things that can interfere with a system.
http://www.sevenforums.com/tutorials/2495-services-start-disable.html
If you've built your machine yourself, and are overclocking, you really need to do some BURN in testing..
a tool CPUBURN will raise the temperature of the CPU a LOT.....
I really recommend that you stress the heck of your system, as that is exactly what an NLE will do....
There are lots of free benchmark tools that can be used to stress your system....
http://www.makeuseof.com/tag/5-free-benchmark-
programs/http://www.softpedia.com/get/System/Benchmarks/IntelBurnTest.shtml