Upgrading Need Suggestions!

[Kappu1]

This is my current system setup-

* Intel Pentium 4 3.6GHz, (800 FSB) 1024K Socket 775
* Spire DiamondCool Socket 775 Intel P4 EXTRA QUIET Copper fan
* ASUS P5ND2 Deluxe nForce4 (dual core),SLI PCI EX, DDR2, SATA,1GB LAN, iEEE
* When choosing memory please refer to board's specifications for compatibility. Check more info
* 2GB (2x1GB) PC4200 DDR2 533 Dual Channel
* When choosing video card please refer to board's specifications for compatibility. Check more info
* GeForce 7800-GT 256Mb DDR PCI EXpress 16X dual head, tv out
* 250.0GB Maxtor 7200rpm SERIAL ATA UDMA 150 8m Cache
* Optorite 16x DVD Recorder Dual Layer +R/RW -R/RW
* Mitsumi 3.5" floppy disk 1.44 Mb
* AC 97 32 BIT Full Duplex sound card (onboard)
* 10/100 Network card adapter (onboard)

What I would like to know is if I can run a Duo Core Processor on my board as long as it is a 775 Socket, I have read through the User Guide and it dosn't really specify and I would like to upgrade CPU, Graphics Card and get another stick of 1GB RAM. Any suggestions are appriciated.

[Khalil]

This is my current system setup-

* Intel Pentium 4 3.6GHz, (800 FSB) 1024K Socket 775
* Spire DiamondCool Socket 775 Intel P4 EXTRA QUIET Copper fan
* ASUS P5ND2 Deluxe nForce4 (dual core),SLI PCI EX, DDR2, SATA,1GB LAN, iEEE
* When choosing memory please refer to board's specifications for compatibility. Check more info
* 2GB (2x1GB) PC4200 DDR2 533 Dual Channel
* When choosing video card please refer to board's specifications for compatibility. Check more info
* GeForce 7800-GT 256Mb DDR PCI EXpress 16X dual head, tv out
* 250.0GB Maxtor 7200rpm SERIAL ATA UDMA 150 8m Cache
* Optorite 16x DVD Recorder Dual Layer +R/RW -R/RW
* Mitsumi 3.5" floppy disk 1.44 Mb
* AC 97 32 BIT Full Duplex sound card (onboard)
* 10/100 Network card adapter (onboard)

What I would like to know is if I can run a Duo Core Processor on my board as long as it is a 775 Socket, I have read through the User Guide and it dosn't really specify and I would like to upgrade CPU, Graphics Card and get another stick of 1GB RAM. Any suggestions are appriciated.
With a bios update I believe you can use a Core2Duo with this Motherboard.
I would add a gigabit lan card instead of the onboard LAN. Not sure if adding another stick of memory will help much with what you say you do with this machine.
Video card You can go with an 8600GTS but do yourself favor and get a quality new power supply before you do any upgrading. Not sure what you have but its always a good idea to replace the power supply if you doing any upgrades on a machine that is more than a year old, in my opinion at least.
Here is a nice 8600GTS from newegg http://www.newegg.com/Product/Product.aspx?Item=N82E16814130084
here is a good solid power supply for a reasonable price http://www.newegg.com/Product/Product.aspx?Item=N82E16817104037
Any core2duo will shine for you. I recommend the E4500 http://www.newegg.com/Product/Product.aspx?Item=N82E16819115031 or if you want to spend a little more and get a beefier CPU you can get http://www.newegg.com/Product/Product.aspx?Item=N82E16819115032

I am not sure if your motherboard will work with the Conroes or not, I could not find anything to indicate that it can.
Good luck