I want to know is it possible to upgrade my xbox 360 too be able to do full 1080p and get better FPS?
I don't think so. Although, I'm not exactly a leading expert in console hardware, but I'm assuming you would need to buy the newest version of Xbox 360, which still won't offer many more improvements over your current console.
Exactly what game are you having troubles with? Some are hardcoded to only allow 30fps, although Xbox 360 seems like it allows for more than that with some titles.
I'm not sure that there is much you can do with its resolution, the most I've heard of is really just hard drive replacements and repair and replacement of the same parts.
Well I've been playing GTA IV alot on my 360 and it seems kinda laggy and I cannot get it too run at 1080p
It's a rather old game, I'm not sure many people needed support for 1080p back then. Was that even released on Xbox 360? I don't remember.
Short answer: no.
Armorfordreams;5591283I want to know is it possible to upgrade my xbox 360 too be able to do full 1080p and get better FPS?
Given your... limited knowledge, I feel I have to ask:
Do you have a 1080p-capable TV/monitor?
Note: If you have an older TV (2005-ish), it may very well not be able to accept a 1080p signal, even if advertised as 1080p.
RE: upgrades, as Zam said, no. If you want it to be upgradable like a PC, get a PC. There's a reason people build and game on PCs instead of consoles. You've learned the main one the hard way.