TSAssist.exe will randomly cause a small somewhat malformed popup to appear in the bottom right that lists a name of a program that you currently have installed and suggests that its time for an update. It appears to choose these programs randomly. If you click on it to start the update, it will happily download and install a sizeable payload of annoyance-ware and occasionally something that's truly a virus. I made the mistake of clicking on it yesterday, not realizing that the update notice was bogus. Before I knew it, weird "IT Help" icons appears on the right corner of all of my windows and my Norton Antivirus said that it had caught and wiped out a known high-risk virus. The worst was this web browser addon that it installed, causing a hover over all Amazon item links to cause a popup to appear showing a bunch of unrelated advertisements in nice neat squares. I was able to easily remove all of the annoyance-ware, but I hadn't realized what had installed it. At first I suspected the update of Notepad++ as being infected, since this is what I was updating. After I thought I cleaned my entire system and rebooted, I saw the same malformed popup in the bottom right saying that I should update Skype. Knowing that the Skype updater looks completely different, I got curious and found the true source of my problem...
Yes, this innocuous "File Type Assistant" program was the one generating those update popups and happily pulling down payloads of dubious origin. I traced it to a process called tsassist, found the directory and realized I could get rid of it.
(1) Use Microsoft Windows "Uninstall Programs" facility to uninstall File Type Assistant. When you click on the uninstall link, a popup will appear pleading with you not to uninstall it. Uninstall it anyways.
(2) Go to the Start Button and in the search/command entry box enter: regedit
(3) In regedit, use the Find menu and type in tsassist.exe. Delete every instance of tassist.exe that you find. It's in several places. If it's in a registry key that only refers to it, delete the entire key. If you see any other programs that you are familiar with, just delete the key entry for tsassist.exe and leave the key alone. (I found just one instance where tsassist.exe was listed next to another key)
(4) Restart Windows.
It hasn't come back from the dead, so I'm fairly sure that this procedure is all you need.
Good luck...And don't click on an Updater unless it looks professional and legit !!!