yes you can. This is what crucial offers Dell Inspiron 15 (3542) | Memory RAM & SSD Upgrades | Crucial UK
Inspiron 3542 - Can I replace the HDD with an SSD  ?  The HDD is quite old now, and the performance of the laptop is very poor. Is there a posibility that I can take out the HDD and replace it with an SSD please ?
Can I replace the HDD with an SSD ?