Can somebody please figure this out for me!!!?

ok, see if you can follow this... my sister bought a new pc a month ago which a neighbor of theirs, who does computers for a living, hooked it up via a router. he downloaded avg free edition on it for virus protection but On the Bottom Right Tool Bar there is a RED %26 WHITE X that says there are MULTIPLE SECURITY PROBLEMS with your computer. i go too security center ( they have vista) and it says it is not detecting any malware protection but avg says it is up to date and working properly. if that isn't strange enough it also says that windows defender is off BUT THEIR NEIGHBOR SAYS IT IS ON BUT HIDDEN! HUH? i know this guy knows a lot more about computers than i do but something does not sound right. she just spent a lot of money on this and i want to find out if she is properly protected. WHAT GIVES?? HELP!

Can somebody please figure this out for me!!!?auto protect

Windows doesn't detect all antivirus programs, and AVG may be one of them. If AVG is running and updated, the computer is safe.

Can somebody please figure this out for me!!!?downloads

Make sure all of AVG is updated. I just installed it a few minutes ago, and ran the updater, it updated it but only the software itself. It left out the virus definitions. Windows still told me that computer was at risk because of no anti-virus software, then it went away when I updated the virus definitions. Open up AVG and check updates. Install all the ones it finds.

About Windows Defender to make sure just open it and make sure it's turned on. I don't see how it can be "hidden" if it is on it should be displayed on the task bar, but it is possible that you can hide the icon, I haven't messed with it so I don't know. To be safe visit Microsoft.com and just download Windows Defender and re-install it.
Uninstall AVG and reinstall AVG for Vista http://free.grisoft.com/doc/2/ Then look for bit defender right click on my computer go to security WIN XP
Their First Problem Is That They Have Vista, but they should try reinstalling avg and then contacting the avg help center. see if that helps