Unlike hard disk drives, solid state drives don't have to move any mechanical parts to access data, so switching your boot drive to an SSD reduces disk-reading time complexity as much as teleporting speeds up long-distance travel. (ref 1, page 1, Disk Delays) Physically installing an SSD is no different than installing an HDD, but you must configure your operating system and computer firmware to optimize them for an SSD.
Replacing Your Old Hardware
When you replace an HDD with an SSD, you can either migrate your existing OS from the old drive by cloning it or install a fresh copy of the OS. Cloning your drive requires a destination partition at least as large as the source, and since SSDs are usually smaller than HDDs, you must back up and remove any unnecessary files from the source that make it bigger than the destination.
With your computer unplugged, connect the SSD to an available SATA slot, leaving your HDD connected as well. Alternatively, replace the HDD with the SSD and then connect the HDD to your computer with an external drive enclosure. A USB drive enclosure converts your drive's SATA connector to USB format so that you can use it as a removable medium. To boot from an external drive, select "Temporary Boot Options" or a similar choice from your BIOS splash screen, then choose your external USB hard drive from the boot options.
Cloning Your Boot Partition
Before cloning your HDD, defragment it using the Defragment and Optimize Your Drives applet. Select a partition, then click "Analyze" and "Optimize" to defragment the drive if necessary. Shrink the partition to fit the new drive using the Disk Management utility; press the "Windows" key, type "diskmgmt.msc" (without quotes) and press "Enter" to open it. Right-click the partition, choose "Shrink Volume" and then, in the field next to "Enter the Amount of Space to Shrink in MB," enter the number of megabytes to remove from the partition so that it fits on the SSD. Migrate the files to the new SSD using a disk-cloning program such as Clonezilla, EaseUS Todo Backup or Acronis (links in Resources). Each of these programs works differently, but they all contain an option to directly migrate files from the old drive to the new one. Select this option from the main menu and then choose the source and destination drives when prompted.
Installing and Tweaking the OS
When you don't have many applications installed on your HDD, installing a fresh version of your OS is a little easier than cloning since it doesn't require extra software. Installing an OS on an SSD is no different than installing one on an HDD, but using the SSD as a boot drive takes some minor tweaking. Enable Advanced Host Controller Interface for the SSD by opening Regedit and choosing the following directory:
Click "msahci," then double-click "Start" and confirm that the DWORD value is set to 0. Confirm the same setting for the Start DWORD in the pciide directory. Restart your computer and enter the BIOS utility, then choose "Storage" or a similar BIOS option. From your SSD's storage options, choose "AHCI" so that Windows recognizes the drive as an SSD. Before exiting BIOS, open the Boot options menu and follow the on-screen instructions for placing your SSD first in the device boot order.
Optimizing Your System
After booting back into Windows on the SSD, open Defragment and Optimize Your Drives, then select your SSD from the menu. The applet displays Solid State Drive next to the drive letter, now that Windows recognizes it as an AHCI device. Since it's an SSD, Windows knows not to defragment it, which shortens its lifespan by superfluously writing and erasing bytes. Instead, Windows automatically enables a feature called Trim that optimizes SSD performance. Trim is a special command that your OS sends to your SSD to make up for the difference in how SSDs and HDDs treat data. SSDs access data instantly, eliminating the several seconds or minutes an HDD takes to move its mechanical arm over a platter looking for data blocks that become fragmented when the disk spins. The drawback of using as SSD is that, after writing and deleting data 10,000 to 100,000 times, the flash memory deteriorates and no longer stores data. To prolong your SSD's life, store documents, media and other files on a large HDD storage volume.