iTunes 8 install probs on Vista Prem 64bit

I just bought an HP loaded with MS Vista Premium 64bit. I have
downloaded iTunes 8 (says compatible with Vista 64bit). I have
downloaded onto my harddrive and right click on it to run as
administrator. I keep getting the same 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."

btw, have no support personnel except these fora.

Can anyone assist? Thank you.

dvb

I am also having a problem with iTunes and Vista, but 32 bit version. I
just got an iPod and am trying to download iTunes to my system. I can
download the software, but can't get it to install. I keep getting the
message that QuickTime (which, according to the website, must be
installed for iTunes to install and work) did not install. I have turned
off my firewall, my virus protection and anything else I could think of
that might be preventing this install. But nothing has helped.

Thanks for your help, Cathy