I have AVG which scans my computer every evening making my computer very slow and finding several files which it changes. They are: Kernel32.dll wsock32.dll user32.dll shell32.dll ntoskrnl.exe These are changed by AVG, but not to be changed again the following day. What can I do about this? Do I need to scan my computer every day? It takes almost 3 hours during which time my computer is painfully slow.