Can't stay logged in?!?

[Alexandra]

This started happening recently and I don't know why. I can't stay logged in on anything! For example on Youtube, Twitter, and a bunch of other sites I usually go on I like to sign in and I usually stay logged in. Now each time I close the browser or navigate away or come back on another day I'm logged out! It's really frustrating. What could be the problem and what can I do to fix it? I think it might be related with my laptop maybe.
Oh yeah gonna add, I do check the little box that says "remember me" :o

[Pinky]

i'm guessing you have softwares that clean up your pc. so they delete your cookies (needed to stay logged in) for privacy purposes.

[light maroon]

your computer is infected by malware or adware or maybe jokes program.It come when you downloading or installing software or torrent.

Download IObit from download.com and scan.it would help.

[LaMBz Maxim]

Yeh, maybe some software from your pc have clear your cookies. You should check the browser option. Adjust anything that you think it's related to the problem.

Oh yeh! When you want to logged in, you write your username and password, but maybe you forget to check the box, which sound like this 'keep me logged in' or maybe 'remember me'???