A lagging PC is the result of a number of system issues, such as data corruption, bad files, low disk space, and bad software. You can use a few Windows tools to speed up a slow computer. Do a little backtracking to find the problem.
Run Disk Defragmenter
Step 1
Press the Windows button. Click "All Programs" and open "Accessories".
Step 2
Right-click "Command Prompt". Choose "Run as Administrator".
Step 3
Type "defrag X: -v" in the prompt, X representing the letter of your hard disk. For instance, if you want to defrag drive E type "defrag E: -v" in the prompt. Press "Enter".
Step 4
Wait for the defragmentation to complete. Reboot your system once it is complete.
Run Disk Cleanup
Step 1
Press the Windows button. Type "Disk Cleanup" in the "Start Search" field. Press "Enter".
Step 2
Click "My Files Only" when the Disk Cleanup Options prompt appears.
Step 3
Choose the drive and click "OK". Allow the tool to scan for possible space to free up.
Step 4
Place a check by the files you want to delete. Click "OK".
Step 5
Click "Delete Files" when the "Are You Sure You Want To Permanently Delete These Files?" prompt launches.
Scan for Harmful Software
Step 1
Press the Windows button. Click "All Programs" and open "Windows Defender".
Step 2
Click the "Scan" option toward the top of the window.
Step 3
Choose the repair option once the scan is complete. Reboot your system once the repair is complete.