Do U have an antivirus?
On the startup and the service tab, uncheck things that aren't necessary and aren't vital to Windows, click Apply.
Go online and download CCleaner or TuneUp utilities (just google them , they're very easy to find), download, install and run.
Do a scan with Malwarebytes, just in case http://www.malwarebytes.org/products/malwarebytes_free/
Go to Control Panel>Add remove.
Look for things U don't use anymore, and uninstall them.