Hello! Long time no see!
I have a question considering my homepage. You see, the other day I saw that there was a video I supposedly downloaded a long time ago. I couldn't remember what it was, so I tried to open it, only to find out I couldn't. So, I opened Google Chrome and went to download a Repair System. After the download, I tried to open the file, only to find out I could not. I opened Chrome to find out an answer, only to find out my homepage has been changed! It is now Blekko, but it was originally the 'New Tab' page.
Can someone help me? Thanks!

I did a little bit of searching and found two things:

1: The Wikipedia page on Blekko apparently cannot be trusted.
2: Simply changing your browser's homepage will fix the issue.

If that doesn't fix it, you will have to open your HOSTS file via notepad.
If all else fails and you're still seeing issues, this page seems to have an answer to removing blekko.

Sometimes when you install specific content from the internet, they can alter your homepage settings. Like, I installed this one program, I forgot what it was, but it installed this toolbar to Internet Explorer(which I don't use), and changed my default search engine to Ask.com.
Now the part I'm confused at are the parts where you say "only to find out I could not". That I don't know. It does sound like a virus if it's preventing you from launching certain applications. Judging by what Quad said, "The Wikipedia page on Blekko cannot be trusted" then it makes sense.