Switching from an NVidia video Dell D630 to and Intel video Dell D630

Recently, I made the switch from an NVidia machine where the chip burned
out to an Intel version. I did so by swapping the Hard Drives from the
old machine into the newer Intel version. I was told I'd need to also convert
over the video drivers.

However, after swapping the drives and powering up, I've found the new machine
to appearently be running fine right off the bat.

I have swapped the drives and powered up and briefly tested most aspects of the new
machine, and it has run far better than I have expected. In fact, it appears to
be running fine right off the bat.

On first power up, I sat there with thumb drive in hand ready to copy and convert over
the video drivers (from NVidia to Intel, remember?), but found that the machine seemed
to be working perfectly well as it was....

Given the situation, and my cautious nature to avoid "fixing something that ain't broken",
is it still necesary to switch over to these new video drivers?

Everything I've seen so far in the operation is working identical to how it did before
on the old NVidia equipped machine, except that it is a bit slower now....but I understand
that that is because the NVidia chipset was supposed to be a faster gaming chipset.

I have only two games on my machine, Ron Monsen's "EagleLander3D" and Martin Schweiger's
"Orbiter 2006". EagleLander still runs, but slower, but Orbiter fails to run due to an
error message of -

   "Initialising 3D Environmnet with a hardware device failed.
         Try again using a software device."

The games aren't terribly important to me on the laptop, so other than that, is it
still vital for me to switch over to the new drivers? Are there other factors involved
that don't show up on the computer screen itself? ....and.... Might switching the drivers
deal with that above mentioned error problem? What are the risks either way?

Thx;
Dave

old machine=
Dell Latitude D630 laptop
Win XP Pro svc pk 3
Intel Core 2 Duo, 2 Gig mem, 120 Gig HD
NVIDIA Quadro NVS 135M video chip
DVD RW drive:  HL-DT-ST DVD+-RW GSA-T21N - Drive(D:)

new machine=
Dell Latitude D630 laptop with the Intel video chipset, and the hard drive from above
Win XP Pro svc pk 3
Intel Core 2 Duo, 2 Gig mem, 120 Gig HD
Intel GM965 Express video Chipset
DVD RW drive:  HL-DT-ST DVD+-RW GSA-T21N - Drive(D:)