Some of the common symptoms of computer virus infection include slowing your computer: The computer works much more slowly than usual. Takes a long time to open applications or programs. The operating system takes a long time to perform simple tasks that usually do not require much time. Inability to run a program or open a specific file;
Disappearance of files and folders: files stored in specific folders (usually those belonging to the operating system or certain applications) are deleted or rendered inaccessible to the user. Inability to access the contents of files: opening a file, you receive an error message or just does not open. A virus may have changed the File Allocation Table (FAT), causing the loss of addresses that are the starting point for locating files.
Unexpected or unusual error messages: Displaying dialog boxes containing absurd, funny, naughty or aggressive messages that require Anti Virus Support. Reduction of memory and hard disk space: significant reduction of free hard disk space, and when a program is running it displays a message indicating insufficient memory to do so (although this is not true).
