You can install by bootable pen drive its a better idea for you and you can take Technical Support for this because its a technical issue and with out technical help you can not repair this problem in a easy way.
Most of us have suffered something similar. The only sure cure is to do a fresh install of the OS. (And if possible... remove the laptop drive and mount it as a slave drive on another machine... where you can run a Low Level Format utility to be sure to wipe the Master Boot Record.) We often spend MUCH more time trying to save our existing setup than it would take to reinstall everything. After you do the fresh install, suggest you use imaging software (Acronis, Macrium, others) to make images at various stages so that you can recover quickly should this happen again. (Imaging software is sort of like Windows System Restore.. except the image is saved on some external medium and is much more robust.)
My laptop got hit by viruses a couple of time recently. Both times I could Google and pin-pointed the exact virus. There were articles on how to "take it out" by editing registry and all that. I don't trust any of that. Many of those steps could not be performed when the virus has taken over anyway. Both times I used Acronis to restore to a good running OS and then restore my data files. Not sure if Acronis is available to your hardware. The time saving from having to re-install Windows and then all your apps... it is well worth the 30 bucks or whatever.
many thanks to all finally got it done...i reloaded it from an 8 gig usb stick it drove me mad i have set up a restore point #many thanks to all