Help me... I don't know which DDRam is combatible to me...
Here are my specs ...

--------[ CPU ]---------------------------------------------------------------------------------------------------------

CPU Properties:
CPU Type Intel Pentium 4, 1400 MHz (14 x 100)
CPU Alias P68, Willamette, A80528
CPU Stepping D0
Instruction Set x86, MMX, SSE, SSE2
Original Clock 1400 MHz
Engineering Sample No
L1 Trace Cache 12K Instructions
L1 Data Cache 8 KB
L2 Cache 256 KB (On-Die, ECC, ATC, Full-Speed)

CPU Physical Info:
Package Type 478 Pin uPGA
Package Size 3.50 cm x 3.50 cm
Transistors 42 million
Process Technology 6M, 0.18 um, CMOS
Die Size 217 mm2
Core Voltage 1.75 V
I/O Voltage 1.75 V
Typical Power 55.3 - 75.3 W (depending on clock speed)
Maximum Power 72 - 100 W (depending on clock speed)

CPU Manufacturer:
Company Name Intel Corporation
Product Information

CPU Utilization:
CPU #1 20 %

--------[ Motherboard ]-------------------------------------------------------------------------------------------------

Motherboard Properties:
Motherboard ID 62-1128-001131-00101111-040201-SiS645$P4S5A_P4S5A RELEASE 11/28/2001
Motherboard Name ECS P4S5A

Front Side Bus Properties:
Bus Type Intel NetBurst
Bus Width 64-bit
Real Clock 100 MHz (QDR)
Effective Clock 400 MHz
Bandwidth 3200 MB/s

Chipset Bus Properties:
Bus Type SiS MuTIOL
Bus Width 16-bit

Motherboard Physical Info:
CPU Sockets/Slots 1
Expansion Slots 5 PCI, 1 AGP, 1 AMR
Integrated Devices Audio
Form Factor ATX
Motherboard Size 240 mm x 300 mm
Motherboard Chipset SiS645

Motherboard Manufacturer:
Company Name Elitegroup Computer Systems
Product Information
BIOS Download

That motherboard accepts either SD-RAM or DDR RAM, but you cannot use both together. If you wish to add extra RAM to upgrade, you will need to get more of the type you currently have installed.

It will accept SD-RAM of up to PC133 speed, or DDR-RAM of up to PC2700 rating.

Download and install CPU-Z Run it and check the memory tab to verify what type of RAM you currently have installed.