Vista - User Accounts don't run certain programs

When I originally set up my computer, I only put one user account on it along
with the Guest account. Recently, I set up user accounts for my family
members - all as admins. However, certain programs won't work on any of their
accounts, but they work on my account & the guest account.

Example - I have AOL Instant Messenger on my computer & it works fine on my
account & the guest account. However, when I try to open it on any of my
other accounts, the program flashes on the screen for a second and then
disappears, and will not open. I have tried uninstalling and reinstalling the
program on the other user accounts & that has not fixed the problem.

Example 2 - When I use the Google Image Search on my computer, all the
pictures show up fine like usual. When I search for the same image (something
simple like "cat") the search says that it has found several million (or
however many) results but none of the pictures show up.

I deleted and re-set up the user accounts, but that did not solve the problem.

Any idea what's wrong? Thank you!