Restarting often get black screen saying no operating system

Hello, i was watching a movie on my laptop(windows7) the other night when everything froze big time.. couldnt unfreeze from task manager so i manually shut it down. Upon rebooting my computer was still frozen taking around 10 mins to respond to each click. I eventually got into my recovery and reset to factory settings wiping my c drive.. this usually solves any problems however after restoring my comp is still running a bit slow. Some updates are working and some are failing.. when restarting i now often get a black screen saying no operating system found, or sometimes disc error and sometimes it boots fine. I have run disk check but no issues found!
The main problem now is that although i have internet connection and my laptop is connected to it with full signal, but my browser isnt working!
It is ie8 but i have had no updates for ie and it just wont work. Without internet access i am struggling to think what to do to fix this. I have followed a few online fixes for browser not working but nothing has helped!
Would greatly appreciate any help/advice anyone can offer?
Thanks!

Would like to add that my laptop is running much slower than before.. hd movies are all jumpy now and games i have always played with no problem are now too jittery to even play.. my ram and cpu and hdd seem to be ok when i run tests but something has gone seriously wrong somewhere.
Thanks again!