It could be language issue...
But even from the data provided in the original post,
Computer Memory Controller
Location : Mainboard
Error Correction Capability : None
Number of Memory Slots : 2
Maximum Installable Memory : 2GB
BANK 0 - DIMM0 : Samsung 0x4D342037305436353534455A332D43453620 0x040AA7AA Unknown DIMM Synchronous DDR2 512MB/64 @ 533MHz
BANK 2 - DIMM2 : Hynix (Hyundai) 0x48594D503136345336344350362D59352020 0x00007140 Unknown DIMM Synchronous DDR2 512MB/64 @ 533MHz
We see he has 1GB installed (2x512MB@533MHz). The very best he could do is to replace each
512MB 533MHz memory stick
1GB 533MHz memory stick
and run in "dual-channel" mode (which this computer does support)
for a total of 2GB (2x1GB@533MHz)
I could not tell with 100% certainty
from the provided info or the specs page pointed to by micro if the computer supports a single 2GB 533MHz stick of RAM. The specification's phrase "...upgradeable to 2 GB using two soDIMM modules..." STRONGLY suggests
the maximum size of any single memory stick is 1GB...but even so, he should
get better performance running in dual-channel mode wtih 2x1GB memory modules.
edit to add:
Oh, and Issen Na...you can buy memory modules that are faster than 533MHz and they should
work, but they will NOT
run faster than 533MHz, but will likely cost you more money.
Note: while increasing your computer from 1GB of total RAM to 2GB total RAM will
help your computer run incrementally faster, it MAY not make much user-noticeable difference, and MAY be disappointing to you. It MAY not be worth the money you spend. It depends on what operating system you use and what applications you use, what you use them for, and how many you use at any given time.