I am a new faculty in US based university. Surprisingly, when I arrived to my new office, there was no computer in it. I wonder, if I will buy a computer with my startup, would I be able to keep it for myself when I will leave the university?
In general, equipment purchased with university-provided funds belong to the university, rather than the individual faculty member who ordered the items. On the other hand, items procured through individual grants (where the university did not directly provide funding), can often be transferred from one institution to another.
However, it is also true that such property is not normally something that you can normally keep for yourself! The primary exception to this might be if the property has been in service long enough to be declared "obsolete," and no longer needs to be inventoried. Then, the university will typically have some sort of policy on the disposition of such equipment, and that is what you should follow.