To begin with, remove Spybot and all its programs... including Teatimer. Remove modem on hold, unless you really use dial-up and that modem on hold program. Remove Crawler, and other programs you do not use.
Then run scans with SpySweeper or MalWareBytes, or Spyware Doctor, as well as another antivirus program other than Symantec... such as Avira Antivir, or AVast...
Then defrag your system.
Tell us the computer, and the setup configuration, including memory installed..