Whenever my laptop gets slow I check task manager, and there are always processes with no description, like winlogon.exe, svchost.exe and csrss.exe (I checked online and apparently these three processes are part of Windows). Moreover, when I connect internet after a long time of being offline, I see an update.exe process (or even two) with no description, which usually disappears in seconds or a few minutes (it also disappears if I disconnect). Is it an automatic update of some program or a trojan? (it can't be Windows updates because my Windows update setting is set on "check for updates but let me choose whether to download and install them"). My Avast free and Avira free (both real time) are up to date and full scans find no malwares whatsoever.