depends..

It is advisable check the PC performance if its both desktop and laptop are HARD WIRED to the modem or router.

run www.speedtest.net and see the difference.

www.speedtest.net not only gauge the internet connection but also computer performance.

and also it depends on the PC specifications.

A lot of things affect wireless connectivity such as EMIs, proximity, etc

also check for viruses, start up programs configuration etc.

hope i helped happy