My laptop is very slow what parts should I change?

Hi @mosiabh

8GB ram is usually recommended for good performance with Win 10.

According to the specifications, 8GB is the maximum amount supported by the laptop and as your laptop has only 1 memory slot you can replace the 4GB ram module with an 8GB DDR3L 1600 SODIMM memory module.

Ensure that you get a DDR3L and not a DDR3 module as the memory in the laptop works at 1.35V (DDR3L) and not 1.5V (DDR3).

If you replace the HDD with an SSD you will notice a performance improvement as well. You need to get a sata 2.5" 7mm SSD which comes with a 9.5mm spacer. This ensures that the SSD sits properly in the existing HDD enclosure in the laptop and to make sure that the connectors line up. The spacer is placed under the SSD to raise it to the correct height.

Most SSD come with cloning software and information as to how you can transfer the data from your HDD to the SSD and have a seamless changeover.

Here's a link from a supplier that may help, just to give an idea of prices for the ram and SSD. Here's a link about upgrading that may also help.

Here's the ifixit Dell Inspiron 3542 guides that will help you to replace the HDD and the ram module