i recently cleaned the system by removing all the connections and then i turned on the system it worked fine..
after 6 hrs i switched of the system .. after an hour when i turned on the system it showed boot failure..
I removed and inserted the connection again even then the hard disk in not being showed in the BIOS also.
i then used the acronis boot cd
from that i could view all the drives and the files were safe...
but i could not boot it ...
then on the next day when i turned on the system it booted and win 7 opened.
but when entered the MY COMPUTER it responded slowly ..
when i tried to install the os again when the system rebooted again the hard disk was not detected..
can any one please help me ..
i have an 250 Gb sata hdd
IMHO Such symptoms could indicate a dying hard disk.
How old is this HDD? What manufacturer? Model?
Check if the power and data cables are firmly connected to the HDD, this might not be cause of the problems but is worth a shot.
I recommend testing this HDD in another computer to eliminate the HDD itself as a problem.
Other things that I can think of are a weak/dying power supply or motherboard controller.
You can also try using another HDD in your computer to see if the system detects it.