Hello, I have a Pentium III 450mhz with an Intel motherboard which has the 100mhz system bus and my operating systems is ME. Previously my memory was two 128mb SDRAM modules which gave me 256mb of memory. Everything was working find until I tried to add additional memory. I could not locate any PC-100 memory and was told that I should be okay installing a 128mb PC-133 SDRAM memory module. Once I installed this module giving me 384mb of memory, I kept receiving error messages while accessing the internet and also not being connected no matter what I was doing. They were exception errors and iexplore error messages. This is what one error message displayed at the blue screen: "exception OE has occurred at 0028:C0011FAB in VxD----- called from 0028:C0012B33 in VxD-----". I removed the older PC-100 memory and just put the PC-133 128mb memory module in and the problems disappeared. Then I added one of the older PC-100 128mb memory modules and still things seem fine but when I then place the third PC-100 128mb memory module in, my problems returned right away. The two PC-100 memory modules were puchased at different time from different sources and they worked well together. The PC-133 memory module was also purchased from a different source but when it was installed my problems began which I had not ever experienced before. Is the memory just incompatible with the other memory modules or is it the fact that PC-133 and PC-100 memory modules cannot reside on the same motherboard in a 100mhz bus? Is there any help or advise someone good provide me? Thank You, Suede.

1. Are you mixing parity-checking RAM with non-parity-checking RAM? I'm not sure if this is still a factor in newer modules. 2. Do you have your motherboard manual? If not, check the manufacturer's Web site. See if it's OK to mix PC100 and PC133 types. My guess is that it's not. You're probably not seeing errors when you mix one of the old modules with the new one because the performance is just marginally acceptable, but then when you insert the third module you're "over the edge". Can you borrow a 128mb PC100 module (of the same parity type)from someone else to do a test? 3. Search the error codes you're getting on Microsoft's Web site, and see what they may be telling you.

Never mix memmory modules (100 Mhz with 133 Mhz)nether ECC with no ECC.Period. You should keep your machine with the 100Mhx modules or buy the 133 Mhz you need, but donīt mix the differents speed modules your windows will be confuse with the hardware configuration due BIOS report a configuration that really donīt exist (the report said memmory bus at 100Mhz and there is a 133Mhz modile o vice versa) this will bring some blue screens (usually happens with memmory or processor with problems)

I mixed 100 and 133 on mine and it works fine.I know of MANY others who also had no problem.Actually mine are ECC and NON as well.The memory will default to the slowest speed and my bios shows it that way.In fact the only people who id EVER heard advise against this are computer mfg and sellers(wonder why that is???).Im sure there are thoes who do occasionaly have a problem(like you) but they certainly arent the majority.I would say that one of the one of the strips is faulty in some way and the added load of it in series is hosing it.Where alone it would be fine.

Thanks for everyone's response. I went back to where I bought the PC133 memory and switched and got a Micron Brand PC133 memory module to play with my current PC100 memory and now I do get the exception errors but now I seem to get a lot of Iexplore, user.exe, MSLS31.DLL and MSDXM.OCX errors now.

i had problem adding 100 speed to existing 66 speed... each of them worked if the other was pulled out... i had to return the 100 speed and i got 66 than everything worked good Regards Miro