Vista Upgrade Problem - Windows Explorer Loop

I have a Motion 1400.

I upgraded to Vista using the Microsoft DVD. I did not use the full install.

Vista comes up but is hung up on searching and finding a solution to a
problem with Windows Explorer. The computer is unable to do any more than
stay with this. Let me explain.

A box appears saying that there is a problem with Windows Explorer and that
Windows is looking for a solution.

A minute later, a box comes up saying that the Windows Explorer does not
work correctly and that Windows was closing this program.

If I do not click the cancel box, the computer seems to stop. By this, I
mean that the clock stops.

When I click the cancel box, the process starts over again and again, and on.

At the beginning, while Windows looks to correct the problem with Explorer,
a box appears and asks for the original disc for Office 2003. This was
installed by the University administrator. I have an Office disc but cannot
install it on Vista. When I cancel the task, the box does not reappear.

Only the Windows Explorer box search-for-solution box appears.

I read on one of your responses a way of getting into the BIOS as a way of
accessing the Vista DVD for a system install. I have some concern doing this
without guidance. At my level of expertise, this is not for the faint hearted.

Is there a solution to this problem such that I can use Vista? Can I do a
full install of Vista now? If not, how can I go back to XP? Will I have to
reformat? I hope that I do not have to reformat the computer and reinstall XP.

Look forward to your wisdom.

Steve S