My laptop compaq 620 sometimes after starting beep sound comes and keys not working and mousepad also not working.the above thing happens occasionally after working on laptop and sometimes it works smoothly
NOTE: If you need to type in a password to even get into Windows to do the following, make sure you attached an external keyboard first, to get past the password. Then disconnect the external keyboard and try the following...
1. Uninstall the keyboard driver.
2. Reboot the computer (without reinstalling the driver).
3. When it restarts, it should reinstall the driver on its own.
If this doesn't work, you may wish to try connecting/reconnecting an external keyboard and see if it works fine. If it does, then it could be the keys themselves that are the issue.
You may also want to try updating the Synaptics Driver if the above doesn't help.
If none of this helps, then I would try starting it up in "Safe Mode" and see if it runs fine in there. You will have limited access in there, but if it runs fine, then I would be looking at a bad program, malware, spyware, virus, etc.