kepub readeble in calibre

I've got the glo,
I bought some books from kobo,
now i have calibre portable on a stick, so i can read any where without my reader and iphone
At my work it isn't possible to instal kobo desktop (security reasons)
But some times i have some time to spare
But the books from kobo aren't visible or readeble
It's not for illigal reason just to read at work
is this possible?