The i3-540 is a first generation Core i processor which runs on an LGA1156 platform using an Intel 5 series chipset. The 6 and 7 series chipsets (including the B75 which you selected) are the LGA1155 platform which is designed for Sandybridge and Ivybridge processors.
I don't know what that power supply is but it is probably dangerous and will likely start a fire.
Sadly with a budget of only $195 you will not be able to upgrade anything well at all. You will need to save up more
My advice.. Save more money.. You're buying an older generation processor, and motherboard that is not compatible as it is a newer generation. DON'T keep the PSU, its trash, the video card is likewise several generations old. For best results you're going to want to save more money all around, but really it depends on what you want to do with the computer.
Oh my god, thank you for letting me know that those components are not compatible, also i forgot to mention I'm from Eastern Europe Macedonia, I want to play some games on low my monitor res is 1024x1024, about the PSU my old processor use more then the i3 but ok maybe the new MB is using more then the old one, what do you guys think just to upgrade the GPU on those old components?
For $125 you could get an hd 7770, which is a really great card for the price. And I recommend this to a lot of people doing budget builds/upgrades, but consider perhaps a phenom ii x4 945/965, can be gotten for around $60 on newegg, $100 for the faster 965, and cheap am3 mobos are a dime a dozen.