I think Vista AERO will not work in Intel 915 chipset. I need some information on it. Does there is a requirement of graphic card or simply the laptop can handle AERO with onboard memory. I am bit doubtful about the same. I am willing to go for fresh updates. If AERO does not work on it without a additional graphic memory then it would be a bit waste of time in upgrading it.
No the chipset does not support AERO. And I will not recommend you to use Vista on it. It is better for Windows XP. It will be more than enough I think. You will waste your time and money as well, in buying up new Vista upgrades. So it will be much better if you can avoid the same. There are also no compatible drivers available that would work for Vista and offer you better output.