Welcome to the forum.
Much of one's success will depend on the source footage, plus the system. What is your source footage?
On the system side, please tell us about your I/O sub-system, i.e. your HDD's, their speed, amout of free space on each, their controller type (SATA II, or other) and how you have these HDD's allocated. This will give us more to go on.
The CPU, though on the low end, should be OK, so long as you are not Importing AVCHD footage.
This is aimed at Premiere Pro, but may help
A link with many ideas about computer setup http://forums.adobe.com/thread/436215?tstart=0
Many of the ideas at the next link are generic enough they have helped some Non-Premiere users fix problems
Work through all of the steps (ideas) listed at http://ppro.wikia.com/wiki/Troubleshooting
If your problem isn't fixed after you follow all of the steps, report back with the DETAILS asked for in the questions at the end of the troubleshooting link
Steve Grisetti has a very useful FAQ Article on how to optimize your OS for editing work. This, plus the other linked article, will get you as much power, as you can get from your computer.
When one gets a "resources," or "memory" error, they must realize that the "resources" mentioned are both RAM and Windows Virtual Memory (Page File). The latter comes into play, when the first is exhausted, which almost always happening with editing video.
That Page File is, just as the name implies, "virutal memory." The difference is that it is hard disk drive (HDD) space, that is allocated to act like physical RAM. It's size, where it's located, and how it is managed in Windows, can make a big difference. For video editing, I like to set the Page File up on probably my fastest HDD, and have its size set statically to about 2.5x my physical RAM. This takes some of the management load off of Windows, so it can do other things. One each of my machines, I always experiment with the location of the Page File (I have several HDD's to use), and test for performance increases, or decreases. On my laptop, I found that having it, managed and sized as per above, on C:\, gave me the best performance. On my workstation, having it split between C:\ and D:\ was my best performance.
Also, a statically managed Page File allows me to give it defragmented space, which it wants, as I can defragment my HDD's regularly, and because the static Page File is the first thing written to the HDD, when I boot up, it's always in the same spot - every time.
Good luck, and hope that this helps too,
Thank you for posting the PrPro-Wiki Troubleshooting link. That was going to be my next post, but you saved me the time.