If it's a netbook I think the processor's going to be weak to the point of being the obvious bottleneck in video editing...
Which is probably why one would want it to work at full capacity and using 64bit words, or at the very least give it a shot.
Go 64, turn off some of the "useless" Aero effects and animations that you barely even notice, disable unwanted services (I mean, the Tablet PC sevice is running regardless of whether or not a computer even has a touchscreen. There's plenty of those that you can get rid of), disable indexing (damn, does that slow down HDD's or what? If you don't use the Search function often, you might as well turn it off) and keep your drive defragmented (Auslogic is a fantastic tool - not only it works better than the stock Windows tool, but it also groups System files in the so-called "fast access areas" of the HDD - nifty stuff). That, and change booting properties to boot with two cores at once (if the processor is dual-core) - boosts the process quite significantly.
That way, you get all the advantages of 64bit processing without putting too much stress on the processor by the background processes.