help with new computer please

i wanna get the most out of my computer and make sure it lasts a long time and is very efficient. I have a new vostro 400 core 2 duo cpu, 2gig memory, E6550@2.33 ghz, windows XP. The computer has no extra's and things like power supply or core temp's or any other things i should be concerened about are now of concern to me. Is there any way i can check the temps inside the case or do i have to buy something for this. Im running a beta application that seems to drastically slow down my computer and at this speed and power im concerened something isn't right. I also have a nvidia 8600 gt vid card. Im not gaming on this at the moment. What extra's should i consider to get max performance out of this machine..thanks

Sorry a little confused. Did you just get a new Dell? If so, what are all the specs, e.g., PSU, hdd, etc

usually prebuilt systems, especially from dell use power supplies that will last for a long time. They usually don't give you more than you need, so when if you ever want to upgrade to a more power hungry video card -- you may want to double check.

if you open the case and look at the power supply, it will have a sticker with all the power supply spec's. go ahead and post them (everything on the sticker)

Most likely, it is the beta program slowing down your system. you could state what program it is and see if anyone here has had the same slowdowns

Power Supply Calculators

Detailed:
http://www.extreme.outervision.com/psucalculatorlite.jsp

Simple:
http://support.asus.com/PowerSupplyCalculator/PSCalculator.aspx