my nexus 7 won't download anything!

[tashal1]

i was using my week and a half old nexus to check my hotmail account, when i went to log out it went a bit strange and kept saying it was downloading something called logout. it wouldnt log me out and wouldnt open these downloaded logout things so i got a bit scared and told it somehow to stop allowing this download. so now it wont when i go to hotmail and click log out it closes down chrome and says it cant do my action or something and i have to sort of clear the cache every time i want it to log out. i could live with this but i then went into google play to download an app and what ever one i try it flashes up for like 1 second this warning saying something along the lines of it cant do it or it just kind of ignores me and just goes back to the screen talking about the app i want. this is driving me insane!!!! please can someone help me :'(