I have bought some new type SDRAM (256Mb, 133, NCP) although seller
told me it wouldn't work on pre-2001 motherboards (at that time I
didn't know mobo was made in 2000). so it doesn't work. windows
crashes on boot with blue screen and BIOS doesn't show text (!), only
colored boxes (((

I was told by salesman it would work at least as 128Mb. Since it
doesn't, does it mean SDRAM is broken? I got some guarantee, and
hopefully they will give me new one but it will be of the same type
If that new module works as 128Mb, is it safe to use it? (computer is
online 24/7)

BTW, I have only two slots and here are some details of my system,
just in case it helps you to help me

CPU-Z Report
------------------------------------
CPU-Z version 1.26.

CPU(s)
Number of CPUs 1
Name Intel Pentium III EB
Code Name Coppermine
Specification Intel Pentium III EB 666MHz
Family / Model / Stepping 6 8 3
Extended Family / Model 0 0
Brand ID 2
Package Socket 370 FC-PGA
Core Stepping cB0
Technology 0.18 µ
Supported Instructions Sets MMX, SSE
CPU Clock Speed 664.5 MHz
Clock multiplier x 5.0
Front Side Bus Frequency 132.9 MHz
Bus Speed 132.9 MHz
L1 Data Cache 16 KBytes, 4-way set associative, 32 Bytes line size
L1 Instruction Cache 16 KBytes, 4-way set associative, 32 Bytes line
size
L2 Cache 256 KBytes, 8-way set associative, 32 Bytes line size
L2 Latency 0
L2 Speed 664.5 MHz (Full)
L2 Location On Chip
L2 ECC Check enabled
L2 Data Prefetch Logic no
L2 Bus Width 256 bits

Mainboard and chipset
Motherboard manufacturer FUJITSU SIEMENS
Motherboard model D1170, S26361-D1170
BIOS vendor FUJITSU SIEMENS // Phoenix Technologies Ltd.
BIOS revision 4.06 Rev. 1.10.1170
BIOS release date 10/27/2000
Chipset Intel i810E rev. A3
Southbridge Intel 82801AA (ICH) rev. 2

Memory
DRAM Type SDRAM
DRAM Size 128 MBytes
CAS# Latency 2.0 clocks
RAS# to CAS# 2 clocks
RAS# Precharge 2 clocks
Cycle Time (TRAS) 5 clocks
Bank Cycle Time (TRC) 7 clocks
# of memory modules 1
Module 0 Hyundai Electronics SDRAM PC100 - 128 MBytes

Software
Windows version Microsoft Windows XP Professional Service Pack 1
(Build 2600)
DirectX version 8.1b