Will my PC able to handle the games coming now-a-days?

I think it can handle games on low or maybe medium, but certainly not any new games maxed out.

What exactly did you upgrade on your PC?

Hello, your PC looks alright for the resolution that you are playing at. Some games you might have to settle for medium graphics presets or high with post processing turned down. Hard to say how it will do in a year or two from now, but worst case you'll just turn down the graphics quality a little bit.

Another thing, if you're into multiplayer games, some of those tax your CPU rather heavily if the game involves more than 10 players in your view at the same time.

So, to answer your opening question exactly, as of today your PC is ok and will be able to run all the games, but not at maximum graphical settings.

I upgraded -

1) RAM- from 512mb to 2.5gb
2) GPU- from 7300gt(512mb) to gts450(1gb)
3)OS- from winxp to win7