my motherboard has 2 slots for sdram memory. i hv only 64mb pc100 memory that's why i want to add 128mb pc133 to my computer.i'm afraid if i put it on my computer it may cause some problem, isn't it?and i wonder if it can really make my computer faster.

64MB is nowhere near enough memory to run windows xp properly... adding a further 128MB would definitely help... as for the PC 133 SD, check your motherboard manual to see if it can accept PC133.. if it can then try the 128 in the first slot and see what happens.. then try adding the old 64MB to the 2nd slot.. some motherboards might not like having a 133 and a 100 ram chip on the same board even if both are supported…. Its touch and go, really 256MB minimum ram is a must for XP You might even want to keep an eye on your local auctions as its easy to get bargains on fairly recent systems (P4 type of stuff 1-3 years old) it may prove to be a good alternative to updating your existing system.

fast memory can go into slower slots if not suported. slower memory cant however go into faster slots if not suported. so sticking pc 133 in will not do any harm. but heres the slightly confusing part if the mother board will take pc 133 and suport that speed then it wont run at that speed. it will adress the memory at the lowest speed which in your case is pc 100 but the motherboard might get a bit upset. matching memory in a computers use to be a bit of a black art. some times it works no problem some times it dosent. all depends on who made it and the size even down to the batch! but whack it in and give it a good extended mem test in the bios and mabey a burn in utility and see if it falls over or throws a hissy fit. if so take out the 64 meg and test again. you could look into getting another pc 130 they must be cheap as hell now so not a large outlay and the more mem you can get the better it will run all text needs typos. There there for the reader to find,to distract them from the total lack of content. google it! wasnt the answer to the question i asked so dont be dense and give me that repl

http://www.crucial.com have a Utility to Scan your system and may be able to identify the correct memory. PC100/PC133 comes in single density and double density as well as some motherboards have a limit on the size, so yes knowing the hardware helps. CPU/Ram: not sure Manufacturer/Model: not sure