can I use photoshop at a library with a portable 10g cloud drive and 500 g hard drive?

I can't download photoshop onto a library or in my area most cyber café computers. Will the portable drive mentioned allow me to do this?

also, can I create high density at least 600 ppi and 24 inches by 36 inches posters very dense and complicated art on an inspiron - is there also

any way to upgrade an old latitude d620 ( dell ) to do this? ALso, I saw a Dell or something aliens 17 with a holgraphi display. I can't find the ad.

has anyone seen it>