First You Should Know About :
Boot : This is When you Simply open Your Computer. When it is powered Off.
Reboot/Restart : This is when you install or Uninstall a software or anything and it needs to restart/Reboot.
Cold Reboot/Restart : This is you hold the power button plain to turn Off.
Warm Reboot/Restart : This is when you simply navigate Through the Start menu to restart.
So What's The Deal?
1. We Should Sometime's Do a Restart for Our Computer To be a little bit Fast. I don't do Restart which is Truth But Restart is a Best way to Have you Computer Back at its own Speed.
2. Cold Reboot is the Most Wrong Way to Restart your Computer its Simply Direct Effect Our Computer Speed, Because its Does not take any time to Save our recent Work.
3. Viruses are the Other Source To make your PC Slow So You Should have Antivirus. In my Recommendation AVAST is the Best.
4. Having Window Installed After Every 4 months is Best To speed Up Your PC.
5. Background Running Software's are Enemy of your Computer So you Know What To Do.You can Click Here to See How to kill Background Running Software's.
6. The Out dated Drivers can also Slow your PC you Should know what to do.