Why does my computer run slowly?

You may have gotten spyware or adware on your computer. Run a good spyware cleaner like malwarebytes which is free from download.com. Also run your antivirus. It could need defragmented so defragment it and clean any old files.

I would also suggest you to scan your computer with an good antivirus and spyware. If you are having any windows operating system then you may try microsoft security essential. It is free and reliable antivirus available from microsoft corporation. You should also check firefox settings and may also try cleaning cache, cookies etc.

It's because your internet connectiong friend. what do you use VNPT or Viettel or ftp, and the paid, how is the paid, total paid or paid by the data you download and upload!

Purchase or download a good antivirus software. I prefer Avira Antivir., it's doesn't require much of a space in your computer. don't surf on a unsecured website, delete unnecessary files.

try to delete some old files you don't need , it may be eating up your memory space, also do install a spyware or malware like iobit(it also have privacy sweeper) and run a scan then run a scan again . this time using your updated anti virus like eset(its light and its good) after which you can defrag it using smart defrag , last option will be to checkdsk(scandisk) to check if there's need to fix a bad file/sector in your pc. good luck

hmm this will be from lot of things. 1st u would not have good internet connection, 2nd i would have a virus (trojan horse) that stealing internel, 3rd do u wave torrent open? it take some internet speed