1. Back Up Your Files.
Documents, photos, videos and other files saved on the computer must be backed up first. If you are using the cloud-based file syncing service, all you need to do is to memorize the account info.

2. Transfer Software.
If you bought licensed software, you surely want them to be activated on the new computer. Applications, such as Photoshop, support the deactivation feature through which you’re able to transfer the license onto a different PC. If you are not sure about the deactivation function available, contact the vendor to acquire the operation instruction.

3. Wipe Your Hard Drive.
After you back up the necessary files, you need to wipe the drive. You can reset and reinstall the operating system to factory conditions to remove all the data. If you are worried about this will not wipe out the data completely, third-party tools are your better choice:
Disk Wipe: https://www.diskwipe.org/
Active KillDisk: http://killdisk.com/killdisk-freeware.htm
AOMEI Partition Assistant: https://www.diskpart.com/free-partition-manager.html

4. Destroy Your Drive
After you are running out of the software options and still feel insecure, you can destroy the drive physically or remove the SSD out to use as an external drive by using a SATA-to-USB adapter, dock, or enclosure.

5. Recycle the Computer
The PC is not allowed to throw away like other usual trash, the electronic parts inside need to be discarded properly. Big box stores like Best Buy and Staples have recycling drop-off points for various types of electronics. Apple and Amazon will also accept their own products back. Moreover, you can contact the town’s district office for e-waste recycling information.

1. SATA/mSATA Speed
The two interfaces have the same speed because the same SATA bus has three versions - SATA 1(1.5Gbps), SATA 2(3Gbps), and SATA 3(6Gbps).

2. PCI-E Speed.
PCI-E interface is based on PCI-E Bus and has different versions and lanes. Generally, PCIe SSDs use PCIe3.0X4 and support NVMe protocol.
3. M.2 SSD
M.2 interface can be divided into two types: B-key and M-key.
l B-key may use the SATA bus or PCI-E 3.0X2 bus, and therefore it may support AHCI protocol or NVMe protocol.
l M-key only supports PCI-E 3.0X4 bus and NVMe protocol.
Their speeds are determined by the bus they use.

4. U.2 Speed
The U.2 interface is based on the PCI-E bus and uses the PCI-E 3.0X4 bus and NVMe protocol.

Your machine won't boot; you get the “No bootable device” or “No bootable medium” error message (on Windows), or a flashing question mark (on Mac devices)
It runs excessively slow.
Active applications often freeze or crash.
Frequent Blue/Black Screen of Death errors.

Capacity Limitations
In most external hard drives, the inbuilt controllers restrict the size of the connected memory to about 4T to 8T.
Price Vs. Quality
Looking at past HDD enclosure reviews would be appropriate other than speculating by price comparison and personal judgment.
Mobility
 it is imperative to consider how easy to handle and carry around it is. The size and shape of your hard drive cover will guide you on how easy it is to arrange and organize your HDDs; especially if you have several external hard drives.
Cooling
Choosing an enclosure with a premounted fan would be ideal. Other storage drives will only require heat sinks. Therefore, ensure that you consider your heat transfer requirements vis-à-vis the noise dissipation by your devices.

1. Move the SSD to a spot with better air circulation, and stay away from the motherboard and other warm components.
2. Buy a better heat dissipation performance SSD enclosure such as one made of metal or designed with thermal pads or fin.
3. If it is the SSD inside your laptop, there is not much you can do. You may contact the manufacturer to ask for suggestions.

Note: Please back up data first in case data loss happens.
1. Check your external hard drive is powered up.
Not all hard drive is powered by the single USB port, some may require an external power source such as AC supply or a secondary USB port.
Check your hard drive to see whether it has more than one USB port and connect it to an AC power supply or a USB cable to the port.
2. Try a different USB port or computer.
Firstly, plugging your hard drive into a different USB port on your computer and if you are connecting your drive through a USB hub, making sure your hub doesn’t need extra power resource. If the above fails, try a different computer, sometimes the different computer systems make significant difference on compatibilities.
3. Check the hard drive is enabled and allocated.
If the hard drive is connected and powered properly, you may need to manually enable it in computer settings.
Start Menu -Typing ‘Disk Management’ – Click ’Create and format hard disk partitions’ – Find your disk on the list of available drives with the ‘offline’ mark underneath it – right click your drive – click ‘’Online.
If this not working, right-click your drive – click’ Change Drive Letter and Paths’.
If you find the word ’Unallocated’ underneath the drive name it means you need to reset it and delete content. Right-click on the drive's name - click ‘New Simple Volume’.
4. Drivers need to be upgraded.
Open the ‘Start menu’ – typing and click "device manager" – scroll down to find your drive in the list. If there is an exclamation point that appears next to your drive, then you need to update the driver.
Right-click on your drive -click ‘Properties’ - click ‘Driver’ - ‘Update driver’ - click ‘Search automatically for drivers’ to search online for a new driver.