It's wired

I can not view some webpage anymore, such as: hotmail.com, can not view falsh video in youtube, either.

I tried to download and instal flash player as youtube guided me to do so, but unlike other computer does, my computer just does not show up the install button, so I could not even install the flash player.

When I use other computer, I found that once I used my account and password, it can not run normally, but if log as a customer, I still run is normally and view hotmail.com page. It is really wired.

Questions:
1.Does that mean my password or log in acct. has been ruin by someone?
2. Is that virus or something?
3. Am I still safe?

thanks,