I know how computers work, but I don't know much about what is good for audio production specifically. My computer I am using is a Dell word processor from 2004 running on XP so in my eyes, anything is better. Because of this, I don't have any sort of view on what I need.
I'm also not exactly dripping with cash either, otherwise I would just get myself a high end computer. I just need something that will last through performances for the next couple of years

I run Fl Studio, NI Massive, and Ableton Live mainly. I would like to run multiple instances of VST plugins (currently I am exporting each synth as a layer, and then re-importing them into a track as a WAV, because my computer can only handle 2 medium end VSTis at a time).
So what should I look for? What sort of specs should I get? Is it possible for me to get a decent laptop, or do I need a desktop? My price range is around 600-700 dollars, and I only need it to last a few years.
Thanks everybody. If this is in the incorrect subforum, please forgive me.