Tidy up by defragmenting the hard drive
Open Windows Explorer. In the left hand pane click on the "+" next to My Computer. Right click on the icon for the "C" drive, it might be called "local disk". Select "Properties" from the list that appears You are now looking at the "General" tab, click the "Tools" tab. Click the "Defragment Now" button..
A pop-up appears showing a list of disks which can be defragmented. Click on "C" (this is usually the drive that Windows lives on). Click on "Analyze" and wait whilst Windows checks the files on the disk.
A pop-up appears, click "close" whatever the message Windows displays.
If more than a few red vertical bars appear in the top part click the "Defragment" button.
Now wait please. If you do this regularly it only takes about 10 minutes. If you have a lot of music or images it will take longer. If you haven't done this for months it will take an hour or more.
When the defragmentation finishes just click the "Close button".
Occasionally Windows will report that are some files it can't defragment, these are usually large files, like TV recordings, or music. Click "View Report" to get more details. In this case you may need to copy the large file to another drive and then copy it back to the "C" drive.