Videos stop and start every two seconds

Until a few days ago I was able to watch videoes on any site, including YouTube, without the constant interruption of buffering. Now it's impossible. I know I'm not the only one who has had this problem, but I have searched and searched for possible solutions thru google and elsewhere and am still no further ahead. I'm at my wits' end. The only thing that happened between the time I could view the videos without interruption and now when I can't, is that the power company installed a new meter at my landlord's house. I was on the computer when the power was turned off and when I rebooted I found that none of videos worked properly. Also, the computer is slower than it was. I use Windows XP and IE; router and wireless connection. I need help.

 

first check the hdd for volume errors my computer right click "C" drive_ click properties/tools/ run error checking
then defrag the drive. If you were viewing a video when the power failure then the file may be corrupt and you will require to get another good video file