The most common cause I find is malware. I use Grif's list of apps to scan and in most cases remove the pests.
Then there are torrent users. That's a whole 'nuther ballgame.
-> Read more at http://www.cnet.com/forums/discussions/how-to-remove-pup-option-603542/#post-f742c795-5881-433b-a29b-6d758efe5cd3
Something is causing random programs on my computer to use large amounts of memory. After I did some updates, my computer started up and was running really slow so I checked the Task Manager to see there were several random programs such as "dllhost.exe," msdtc.exe," "taskhost.exe" all using up 100-500,000K of memory at a time. Even the command prompt, which I don't have open is using up large amounts of memory. I tried running a system restore to yesterday twice, and it failed both times. Any other advice?

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