My BB is recently upgraded to 4.5.0..46 OS.. it is good.. but my BB is very slow.. I have got some themes installed when I was using my BB with 4.2.1.107 OS. Now after the upgrade my BB is very slow. When I check the File free bytes in status in option, it is showing zero. Can some one suggest what to do ?

Shash.

Several suggestions

1) Delete all unwanted themes or move them to the media card. Do this for puictures, ringtones etc. See links about how to optimize your BB memory
2) You can't use ColorPearl, Softreset or Today Plus Theme with 4.5. you need to change to the Regular Today Theme (or one of the other preloaded ones that come with 4.5). There also may be other older themses that do not work well or at all in 4.5. Delete the other noted apps
3) Temporaily remove ALL files from your media card and format it in the 4.5 OS from with in the BB then load them all back
4) Remove/archive/delete all unwanted e-mails. It is surprising how quickly they can collect and fill up the BB.

Hope that helps