Help me upgrade please!

Yes, however the 533 will give better performance than the 400.

The 4850 is about twice a 430. and like clifford said, about where you want to be with your P4
http://www.guru3d.com/article/geforce-gt-430-review/14

so what options will open up if i install the intel pentium d 945 presler 3.4 ghz? which card would u recommend then? and i will be buying the corsair 500 w psu. and 1 gb of ram, or will it not matter?

Going up to the Pent D 945 will definately help you with processor intensive tasks, it is basically 2 Pent4s on a single die. However the 4850/4870 would still be around the max you would want to go on video card. Anything much more would be bottlenecked by the CPU / motherboard chipset. The 4850 is a decent card and can still run most current games at meduim settings. Yous should be able to max out an older game like FSX with a PentD/Radeon 4850.

Ok guys thanks so much, I will drop the processor out for now , ill buy that later. so it leaves me more money for the card, final decision between radeon hd5770 and the 6770 , or possibly the 4850, also even tho the 5770 and the 6770 are pcie 2.1 , will they still work with my pcie x16 slot? and i have 3 options for the 6770 1.xfx hd677x http://www.newegg.ca/Product/Product.aspx?Item=N82E16814150540 2. his http://www.newegg.ca/Product/Product.aspx?Item=N82E16814161387 or 3. his http://www.newegg.ca/Product/Product.aspx?Item=N82E16814161378
thank u guys

or is there anything better then the presler pentium for my motherboard?

Thats top of the line for your motherboard. If you want to spend your money on better performance you would need to change motherboards. Anyone looking to spend over $200 on upgrades, might consider this option. For an extra $100 or so you could build a machine with 10 times the power.

Final Decison : GPU: XFX HD-677X RADEON HD 6770 1GB http://www.newegg.ca/Product/Product.aspx?Item=N82E16814150540

CPU: Presler Pentium D 945 http://www.newegg.ca/Product/Product.aspx?Item=N82E16819116391

PSU: corsair cx500 v2 500 w http://www.newegg.ca/Product/Product.aspx?Item=N82E16817139027

Memory : http://www.newegg.ca/Product/Product.aspx?Item=N82E16820178094

please tell me if all this is compatible with my pc or if theres a better deal

Looks good to me.

You ask a question and I'm not sure if you got a response to the question.

The answer is yes you would need a thermal compound to bond the CPU to the heatsink. Arctic Silver 5 Thermal Compound is what I am using now. Some work better than other but I couldn't tell you which were better and which were worse.

newegg thermal compound search

Ok if i wanted to upgrade my motherboard which one would fit closely to my current motherboard, and how about then what video card should i buy? becuase i wanna keep that ddr2 memory and use my 300 gb hd and cd drives