I had this problem last night , my laptop became dead slow at 1st then while browsing it hanged completely and I could not even start task manager , I restarted it by holding the power button and it showed toshiba logo and then a black screen , with blinking cursor, I turned it off after sometime because it was not booting and started looking for the solution. I found the remove battery n charger , hold power for 60sec thing but when I turned it on before applying the method it booted normally now after some hours it became dead slow so I restarted it by going to start > restart and it restarted but again the black screen and white cursor , So after trying 10 times f8 it did not work (win recovery ) I tried the battery removing thing ,still no help, not to forget num lock light is on , fans are working , but i can not do anything else
I ran a bootable kapersky rescue . it showed no virus, then I rebooted it was the same , i rebooted again n the window booted normally with normal super speed as usual, i shut down twice and turn on and it worked, but when I restarted it when to the black screen again n is still the same.
I remember the 1st time when this happened last night was when I restarted it , because it became too slow,
So now I got a point that it is having problem when restarted.
Now If anyone can tell me a software like the kaspersky rescue which can repair the error or help me start the win repair screen so I can reinstall the window and see if it is of any help or not