Upgrade into a server or buy a new box?

Hi everyone, I was thinking of upgrading my current XP computer to Windows 2003 Server, getting a new CPU and a gigabit ethernet PCI card. But with new servers getting so cheap now, should i even bother upgrading this one, or start fresh? And if I can upgrade, should I do upgrade to a newer mobo? SANDRA tells me I can upgrade to a newer CPU with the same mobo, but I don't know how new...

PS: this server will be for light filesharing for up to 4 people at a time, filemaker server, and http shares to serve mp3s (progressive downloads are fine, i don't need to stream these audio files).


CPU : Intel(R) Pentium(R) 4 CPU 2.40GHz
Mainboard : ASUSTeK Computer INC. P4S8X
Bus(es) : AGP PCI IMB USB FireWire/1394 i2c/SMBus
Multi-Processor (MP) Support : No
Multi-Processor Advanced PIC (APIC) : Yes
System BIOS : Award Software, Inc. ASUS P4S8X ACPI BIOS Revision 1005
Total Memory : 2GB DDR-SDRAM
Chipset: ASUSTeK Computer Inc SiS648 CPU to PCI Bridge
Front Side Bus Speed : 4x 133MHz (532MHz data rate)
Total Memory : 2GB DDR-SDRAM
Memory Bus Speed : 2x 166MHz (332MHz data rate)
Video : RADEON 8500 SERIES
Ethernet : SiS 900-Based PCI Fast Ethernet Adapter