As each successive Windows operating system is released the stress on the
RAM is increased - due to the way the RAM is utilized in the new O/S. Vista
uses the RAM much more aggressively that Windows XP did. Windows XP was a
lot more aggressive with the RAM than Windows 98 etc.

What worked with a prior operating system may not necessarily work with
Vista. You need matched RAM. By matched, I do not mean one stick of PC4200
RAM from Kingston and one stick of PC4200 RAM from Crucial. Get two sticks
of RAM from the same manufacturer, preferably - during the same purchase.
This way you can "almost" be assured that they are from the same batch, from
the same lot - and manufactured on the same day.

Also, buy your *PREMIUM* RAM from a manufacturer such as Corsair or Crucial.
If you use their memory configurator to select the RAM you will be
guaranteed that the RAM has been tested to work in your computer with your
specific motherboard. The above two companies have lifetime warranties. If
you have any problems just place a call. I have received a replacement
before I ever sent the old RAM back. Their service is superb.

--


Regards,

Richard Urban
Microsoft MVP Windows Shell/User
(For email, remove the obvious from my address)

Quote from George Ankner:
If you knew as much as you think you know,
You would realize that you don't know what you thought you knew!

"Bec664" wrote in message
...
I just bought a DELL E521 PC with 1 Gig ram DDR2 5300 , decided to add 1
Gig
more memory DDR2 4200 where from the old system, after install Vista boot
up
slow and black screen. After removing it no problem. Tested the system
only
run at 1 Gig, do I need to reinstall to recognise the ram.