Windows installer problem

ello everyone,

I've been having a problem lately where whenever I try to install something
I get the message "The Windows Installer Service could not be accessed. This
can occur if you are running Windows in safe mode, or if the Windows
Installer is not correctly installed. Contact your support personnel for
assistance". Considering that I AM my support personnel, that message isn't
all that helpful.

I found an article on Microsof that gives two solutions - reregister the
installer, and re-install it. Reregestering it didn't help, and when I go to
the article they list to get the download for the reinstall, I find that it
doesn't have the version for SP3 (which is what I have installed).

I then found a link for Installer 4.5, which installs but does not solve my
problem.

I also can't get my iPod to communicate with iTunes....I'm assuming the two
are related but I guess I won't know until I get the installer thing fixed.

If it matters, I'm running XP Home Premium. Does anyone have any idea how to
get this fixed?