Strange problem when adding RAM to laptop

[CognitiveDissonance]

I am trying to add an additional 256MB stick of RAM to a laptop, and have run into a problem that I don't understand.

First some specs on the system so you know what I'm working with: It is a Toshiba Satellite laptop, approximately 2 years old or so, with a Celeron 1.6GHz processor and a single stick of 256MB of RAM, running WinXP Home with SP2. Until now nothing has been done to it hardware-wise since it left the factory.

When I boot the comp after adding the new stick, the WinXP loading screen comes up like normal, then I get a screen that reads:

We apologize for the inconvenience but Windows did not start successfully. A recent hardware or software change may have caused this.

If your computer stopped responding....

The screen rambles on with some vague instructions that I'm leaving out for now (mostly because I expect those of you with more experience than me have probably seen it before. If the text is important for you to see I will be happy to type it out here, just let me know.) At the end of the instructions I am given 5 choices on how to proceed:

Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt
Last Known Good Configuration
Start Windows Normally

Both "Start Windows Normally" and "Last Known Good Configuration" simply runs the XP loading screen again and returns me to the same screen. All of the Safe Mode options, however, brings up a list of various system files (with their path) beginning with
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS\system32\ntoskrnl.exe
and ending with
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS\system32\DRIVERS\agp440.sys
...and then locks up completely!

***...unable to start in Safe Mode?

As an experiment I tried removing the old RAM and just using the new RAM, in case there was some compatibility issue there that I'm not aware of. When booting this way, I get:

Windows could not start because the following file is missing or corrupt:
System32\DRIVERS\pci.sys

You can attempt to repair this file by starting Windows Setup using the original setup CD-ROM.
Select 'r' at the first screen to start repair.

At that point I got worried that something was seriously messed up with the system, but upon putting the old RAM back in without the new RAM at all, everything works as well as before.

I purchased the new RAM online and the site I got it from stated:
Toshiba Satellite 1415-S105 256MB DDR PC2100

Your Toshiba Satellite 1415-S105 only supports modules made with a specific type of chip. Should you find what seems to be the exact same memory elsewhere for a lower price, it is very possible that the cheaper memory will not work in your computer.

The model number listed is the model number of my laptop, and the factory memory stick is indeed 256MB DDR PC2100, but at this point I am doubting the truth of their claim that the laptop only supports "a specific type of chip".

Obviously something is not right about the new ram. My questions are:
A) Did I get the wrong kind of RAM?
B) Is the RAM correct but defective and just needs replaced?
C) Is there something wrong with the computer that will prevent any new RAM from being added?
D) Did I get suckered? Will the Kingston or Crucial RAM from NewEgg work fine and I should just chalk this up as a learning experience?

[rspassey]

If you enter BIOS does it register the new RAM?

[mystvearn]

a) Did I get the wrong kind of RAM?
No, you did not get the wrong ram. Maybe different latency, but not different ram.
B) Is the RAM correct but defective and just needs replaced?
Yes, I think this is the first choice. imac's also suffer from the same problem. So if you can install the ram on site it will be better, than just purchase whichever that will work.
C) Is there something wrong with the computer that will prevent any new RAM from being added?
No. If it does, it is usually in the BIOS, but additional hardware will be detected automatically.
D) Did I get suckered? Will the Kingston or Crucial RAM from NewEgg work fine and I should just chalk this up as a learning experience?]
I am not sure about this, but best bring it with your laptop and ask for a refund, or just ask them to make it work with your laptop. Bring also the details of what kind of RAM that can work with it as proof to the shop.

[kram 2.0]

Where did you purchase the RAM? I did a recent upgrade myself on my Satellite 1400 (PC133 SDRAM) - I purchased the stick directly from Toshiba to avoid compatibility errors. Worked fine.

kram

[GaryRouth]

Even good vendors have a bad module from time to time. Ask the vendor for an RMA form and return the part for either a refund or exchange.

To see if your online vendor is well-regarded (or not) by it's customers, check at ResellerRatings to see how the vendor is rated http://www.resellerratings.com/

Crucial.com, among others, guarantees their modules' compatibility and carries lifetime warranties. NewEgg is a highly recommended site as well.
. . . Gary

[p.s. ... when changing memory in a laptop: I usually advise removing the battery (as well as unplugging the AC adapter, of course) ]

[glc]

Return the ram and buy a module direct from the Crucial configurator.

[vcuee]

It sounds like the same thing I saw when I preformed the same upgrade on the same model. The problem was that I had put the computer into hibernation, yanked out the battery, and installed the new RAM. When it tried to resume, I got an error. So I shut it off, pulled out the new RAM, started back up w/no problems, actually shut down the computer, installed the new RAM, and have been blazing along happily ever since.