Hash verification is a process that verifies the integrity of a file by comparing the hash value of the downloaded file to the hash value provided by the source1

Resource Monitor will help a technician identify the issue when a user reports a computer is running slow1

The most likely cause of the issue of having different hash values for a downloaded security tool is a modified file. A hash value is a unique and fixed-length string that is generated from an algorithm that processes data or files. A hash value can be used to verify the integrity and authenticity of data or files by comparing it with a known or expected value. If the hash values do not match, it means that the data or file has been altered or corrupted in some way. A modified file may result from intentional or unintentional changes, such as editing, encryption, compression or malware infection. Private-browsing mode is a feature that allows users to browse the web without storing any browsing history, cookies or cache on their browser. Private-browsing mode does not affect the hash value of a downloaded file but only how the browser handles user data. Invalid certificate is an error that occurs when a website or a server does not have a valid or trusted digital certificate that proves its identity and secures its communication. Invalid certificate does not affect the hash value of a downloaded file but only how the browser verifies the website or server's credibility. Browser cache is a temporary storage that stores copies of web pages, images and other content that users have visited on their browser.

Flashing the BIOS, reformatting the drive, and then reinstalling the OS is the best method for returning a computer with a malware infection to service. Flashing the BIOS updates the firmware of the motherboard and can remove any malware that may have infected it. Reformatting the drive erases all data on it and can remove any malware that may have infected it. Reinstalling the OS restores the system files and settings to their original state and can remove any malware that may have modified them. Scanning the system with a Linux live disc may not detect or remove all malware infections. Degaussing the hard drive is an extreme method of destroying data that may damage the drive beyond repair. Reinstalling the OS before flashing the BIOS or scanning with antivirus may not remove malware infections that persist in the BIOS or other files.