Sweep your computer for free by using a system optimization utility, such as CCleaner, to remove unused registry entries, ActiveX controls and application paths and clear out unnecessary temporary files that Web browsers and operating systems generate. To deal with malicious software, use a free anti-malware solution, such as Malwarebytes Anti-Malware, to scan your computer and sweep the sources of computer infections.
Download the free version of CCleaner from Piriform.com, install the program, and run it. Click on the Cleaner button, check the boxes for Windows Explorer, System and Web Browser elements you want to sweep, click the Analyze button to generate a list of files that the utility wants to clear, and click the Run Cleaner button. Sweep the unnecessary registry entries by clicking the Registry button, checking the Registry Integrity box and clicking on Scan for Issues. With CCleaner, you can also remove unnecessary software and applications by accessing the Tools section.
Download Malwarebytes Anti-Malware from Malwarebytes.org, and install it. Run the program, let it automatically update its database, click on the Scan button, select the desired type of scan, and click the Start Scan button. To do a thorough sweep, select the Custom Scan option, check all the boxes in the Custom Scanning Options section, select the Treat Detections as Malware option for unwanted programs and modifications, select all drives, and click Scan Now. Once the scanning process completes, check the boxes next to all detected threats, and click Remove Selected.