xp pro error messages-PC won't boot or recover

Got an memory error message on day 1, but after several auto starts the
pc started.

Now today, nothing, nada. with two errors which are:

At the top of a blue page "Missing or Corrupt NTFS.sys file", then at the
bottom of the page under technical info:

Stop 0x000005 PAGE_FAULT_IN_NON-PAGED_AREA

Read through knowledge base for both errors....

2 years ago replaced one of two 128 ram chips with a 512, been working
great. Per the KB for the page fault, tried swapping all out, found all the
modules except one will at least try to boot the machine, the 128 that was
operating at the time of failure...with just this module installed, PC won't
even power up, so one would thin this module is problemk, removed that
module good to go....not.

Following instructions for NTFS error...bigger problem...using the
installation CD to replace the NTFS.sys file I've tried all three options
after the CD loads, install XP, recover XP by hitting R and exiting by
hitting F3, all three actions give me the blue screen with the errors, then
goes back into trying to boot after a hard power down.

So, pulled out Dell Diagnostic CD...run it through all it's
steps...no errors...leading me to think software only...but the memory is
still nagging me..
Then, exiting the diag wanted to go to command prompt, got C:\\ to come up,
but when I do a dir search in dos, nothing comes up and then it tells the
volume in drive c is MS-RAMDISK... go back to CD root, do a dir. search, no
problem, the dir shows up for the CD rom, swith back to C, nada...can't see
or access anything, no commands work, it's like the C drive isn't there.
(i've always been able to find the C, even with a HD fail)

So, I can't get the install CD to run, the PC won't boot, can't access C
(CMD) via any kind of CMD prompt...can't get anywhere...

Suggestions anybody?

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CTB