OK i am planning to upgrade my CPU from an i5 to an i7. My question is... Can i just take out the old i5 and pop in the new i7 and have everything still work? 2nd. I know this question is not about CPUs, but can if i can just plain old swap out the CPU, can I do the same for a video card?
the video card, yes. that's verry simple. simply uninstall the drivers from the old one, pull it out, insert the new card, and install the drivers for it. that's all it takes.
for the CPU, it depends on what socket type you're reffering to. do you have the 1st gen i5? or a sandy/ivy bridge? that's required for knowing what you can upgrade to. if let's say you have a sandy-bridge i5. then you'll more than likely be able to upgrade to any sandy-bridge i7. same with the other 2 socket types
EDIT: and no, nothing special is required for the processor replacement. litterally shut the computer off, pull out your i5, plug in the i7, and turn it back on. (the time it takes to do this depends on how well you know what you're doing. and you will still have to apply thermal paste and i recommend checking in your bios upon startup and making sure that it recognizes the hardware swap.)
You should reset your cmos and configure it for your new cpu. and like ET said clean and reapply new thermal compound, the video card if you are installing the same brand just swap it out and update the drivers, if not run a driver cleaner available from both top card manufacturers