Here are some pointers if you are replacing your mechanical hard drive with an SSD.

• First update your BIOS.
• Make sure that AHCI is enabled in the BIOS
• Install a program that monitors the S.M.A.R.T. on the hard drive. This will tell you if there are any communication issues between the computer and the SSD. (a BIOS update solved a problem I encountered.)
• Turn off defragmentation software. SSDs should not be defraged. It will decrease the life of the drive.