Advice Requested on Life Expectancy of a PC Windows System

[Jerome H. Fine]

I would appreciate some advice on both the software and the
hardware life expectancy of a PC Windows System.  While
the hardware / software of the second and third system are
almost 10 years old, I don't consider them, let alone the first
system, topics for this list.  But since my goal is to support
running legacy software, especially including the RT-11
operating system for the PDP-11 computer, I request your
indulgence.

At present, I have three systems that I am running:

(a)  A 12 year old system that I am very pleased with that runs
      32-bit Windows 98SE.  I really only use it for e-mail under
      Netscape 7.2 and to run the DOS variant of Erstaz-11 in
      FULL  SCREEN mode.  It consists of a 0.75 GHz Pentium III
      with 768 MB of memory and 3 * 131 GB ATA 100 hard drives.
      The power supply has been replaced, but is still inadequate,
      so a separate PC power supply is used to run the hard drives
      which were also replaced about 5 years ago - the original
      hard drives were only 40 GB each.  Note that while this
      system is a bit slow as compared to the next two systems
      (which are about 4 times faster), it really does everything
      I need to do.  PLUS, the backups are a breeze since I use
      Ghost 7.0 to back up the C: hard drive in about 5 minutes
      every other day producing a single image file of about 1 GB.

(b)  A 7 year old system that my wife uses which runs 32-bit
       WinXP with 4 GB of memory and 2 * 500 GB SATA
       hard drives.  The CPU is a 2.67 GHz E8400 with 2 cores
       and 6 MB of L2 cache, so it still runs reasonably well.
       My wife uses it for e-mail, watching youtube videos and
       google searches.  The system has probably been used
       about 16 hours every day and turned off every night.
       The battery probably needs to be replaced since the
       boot each day needs to reset the date / time when the
       boot hangs at the very start, but otherwise the hardware
       seems OK.  The software is very out of date and needs
       to be replaced.  Note that if 7 years is not a really long
       time for a WinXP system (specifically the motherboard,
       video card and power supply) which has been used for
       between 20,000 and 30,000 hours, then I could upgrade
       this system to 64-bit Win7, double the memory to 8 GB
       and, if appropriate, also replace the disk drives and the
       power supply.  The mother board, video card (which
       supports two monitors) and CPU would be retained.
       System (c) has the identical motherboard as system (b)
       and was considered a replacement.

(c)  A 7 year old system which runs 32-bit WinXP with 4 GB
       of memory and 3 * 1 TB SATA hard drives.  The CPU
        is a 2.83 GHz Q9550 with 4 cores and 12 MB of L2
       cache, so it runs reasonably well.  The system was never
       used very much, probably a total of 200 to 500 hours
       and sat in its box for the past 4 or 5 years until I have
       finally been persuaded to upgrade to 64-bit Win7 and
       double the total RAM to 8 GB, the maximum the mother
       board supports.  I just turned on the system yesterday
       and it runs correctly.  My assumption at the moment is
       to upgrade to 64-bit Win7 and replace my wife's system.
       One aspect that puzzles me is that the video card, the
       same video card as in system (b), no longer supports
       two monitors (which it did and was correctly tested with
       5 years ago).

My first question is if a 7 years old system such a (c) would
be likely to have any serious hardware problems after sitting
idle for 4 to 5 years.  I can't see that any current I7  CPU from
Intel is likely to be much better, so why buy another system?
The hardware has been used sufficiently, so infant mortality
should finished.  But, would a new I7 system be a sufficient
improvement to justify spending the money?  So I intend to
replace (b) hardware and software with (c) hardware plus
4 GB of memory (for a total of 8 GB of memory) and switch
to 64-bit Win7.  Is this a good plan?  Or is it likely that the
motherboard and video card in system (b) is still sufficiently
reliable after 7 years to upgrade system (b) to 64-bit Win7
and use system (c) for something else?

My second question is just how thin is the ice that I am skating
on for system (a)?  If the answer is VERY, then I have one
alternative to buying a new I7 system which would be used to
run 64-bit Win7.  On the other hand, if the motherboard in
system (b) is not too old at 7 years and 30,000 hours, then
system (c) would still be available.  A lot of choices and things
to consider.

Jerome Fine