OK I bought this Motherboard:
http://www.newegg.com/Product/Prod [...] 6813135060
Like an idiot i didn't check my current case and it didn't fit.
So I'm thinking of buying this one:
http://www.newegg.com/Product/Prod [...] 6811164089
And I noticed that th rear I/O panel deosnt match the motherboard's ports.
So am i going to be able to detach it and put on the one that came with my motherboard?  
Thanks in advance.

well, have fun with that ultra slow system....  but you can do that if it fits.

The rear I/O Panel can be replaced by the one that came with your new motherboard. It just pops out, sometimes they can be a little tight so a tap on the corners with a screwdriver handle usually works.

Yes, as inquisitor03 said it will work.
Worst case, you can run it with out the I/O shield.
 
Just be careful not to load it with to many extras.
The included PSU is extremely weak.
 
Not everyone needs a high end system daft.
His machine will still have more than enough power to surf the net, do homework and watch movies.
Hell, I used a Thunderbird 1GHz system with 384Mb ram for a HTPC until I moved over seas a few months ago.
More than enough power for anything I needed it to do.

 
I miss my 1333MHz thunderbird now

My friend has this mobo and he plays all his games on it O_o. Games like Assassians creed, CSS, Bioshock etc... Beside this is a BIG upgrade for me.

 
Why do you say its the worst case?

Worst case as in your new MB did not come with a I/O shield.
It will not hurt anything to run your system with out one.
 
Sorry to say but your system will not be a great gamer.
It is fully limited by the single core Sempron 3000+ that comes with it.
AMD killed the socket 754 off years ago leaving systems like this with no possibility to upgrade.
 
That being said, it will still be powerful enough for standard day to day use.

@OP, I'm not sure anyone is trying to be mean, but the point of all the criticism is that the system you are building will be dramactically slower than even the "average" rigs posted around here.  If you want something that will perform well, post a budget and I'm sure you'll get lots of good suggestions.  If there is no budget, well then your system will handle many things perfectly adequately, but modern games at decent resolution and eye candy turned on is not among them.  Other than an occasional Antec, no one here would ever trust a cheap PSU that comes with a case for a gaming rig, although for a low-end business class PC like that, you might get by with it.

 
I meant to say it did come with I/O shield O_o
But I'm not trying to make a badass computer XD
Looked up reviews on this mobo and people have claimed that they have played allot of the newer games which is fine for me. The only game that I really want it to play is CSS XD
This is my current PC:

As you can see I am only limited to 1.8GHz and its not that good but i can still run allot of the newer games Quake4, TF2, Portal, all the Half-Lifes, and I can even run Assassin's Creed but not that good lol.
 
So like I said in the last post, This is a BIG upgrade for me XD.
Maybe when i get a better job I will make a better computer lol
P.S. My graphics card is an NVIDIA GeForce 7600GS

No, from a P4 1.8 to a Sempron +3000 will make almost no difference.  A RAM upgrade to 2GB would more than double the gains, and the Sempron will bottleneck as badly as the P4 video card wise.  Honestly, you need to take that motherboard and processor back, save up and tell us when you have 200-300 dollars or more to spend so we can hook you up with a REAL upgrade, not something that may or may not work, but something that will perform a little bit less than a much more expensive system.  Honestly the difference between a P4 2.4 and an Athlon +3400 was tiny and the Athlon series is much better than the Sempron series.  I would DEFINATELY use the I/O shield, though rare, not using one can short out the system and this is more common with cheaper motherboards and cases.  I'm not trying to say that your new motherboard and processor suck, they are ok and can get the job done, but the upgrade is NOT worth it.  Also with the 7600 GS you might as well forget about Bioshock, and Assassins Creed, my back up system uses a 7600 GT and I can not play either of those and other games like The Witcher and, of course, Crysis.  If you can not save that much money then take back the motherboard combo and buy a 9600 GT and some more RAM, that will make a huge difference.

Well I just got done playin Assassin's Creed >.>
And besides this isnt goin to be my perminate computer just something to hold onto untill i get a better job (Table buster)
and when i get enough money I will be sure to come back here.
I mainly got this motherboard because it has a PCI-E slot XD.

Well I'm just going to go ahead and keep the mobo I  just bought, because i found someone that wants to buy my current computer for 270 bucks. And this goes out to The_Blood_Raven,
http://www.newegg.com/Product/Prod [...] &x=13&y=33
out of the top 13 which one would be best for me to buy in your opinion?

None, you're going to get bottlenecked to the ground, spend the money on a decent cpu/motherboard like a ga-p35-ds3l and a core2duo e2180.

NEW THREAD TIEM!  
http://www.tomshardware.com/forum/ [...] g-computer
I sold my old computer and got 250$ for it.
But if anyone want to, suggest a graphics card for this thing.

http://www.newegg.com/Product/Prod [...] 6814150277
 
^ That one, it is at an exceptable price, and it is from XFX who offer double life time warranties and who have always been very polite and helpful to me and everyone I know with their above average customer support.  No step-up program like EVGA, but with the double life time warrenty, not only are you set for life, but you can sell a used XFX card for more.  That is my opinion, all the fancy "factory overclocking" makes very little difference, and I'm sure you can easily push it up 50 mhz by yourself and save almost $50 too.