Yes, you can. There is no interdependence between Lightroom 4 and Lightroom 5. I suggest that you record your Lightroom 4 serial number if that was the first version that you purchased. You might need it if you upgrade to Lightroom 6 when it is released, and you purchase an upgrade version.
Thanks Jim. I have recorded LR4 serial number along with all my other Adobe
products serial numbers just for safe keeping. Appreciate the info.
Glenn Bailey, Ph.D., M.A.
"A merry heart does good like medicine." Proverbs 17:22a