Question on Microsoft student edition software

Back when I was in schoo Microsoft had a software deal with my university that allowed me to get Windows XP Pro (32 and 64 bit) and Office 2003 for a very cheap price. This was back fall 2005. In 2007 I got Vista Ultimate and Office 2007 though the same deal for a very cheap price as well.

My questions are as follows:

1. Can you keep using and activating the software once you have graduated? Or do you have to buy new copies?

2. Can you keep using the previous OS if you buy a new one? I got XP through my school and then later got Vista the same way. Would I be able to run both opearting systems (either dual boot or seperate machines), or would buying Vista void my ability to install and activate XP?

ditto

but can only be on one machine so if you dual boot with the OS and its on another machine then you will most likely have activation problems