Did you get your laptop to start again after you took out the battery and put it back in?
Yes It started back. Now its running fine after that hide-and-seek but I just want to make sure there isn't a short circuit bcoz I have to do all my work on it for at least 14-15 months.
I would scan for malware / viruses..........script files that can be placed in your registry
I was coonected to internet but I could open only few sites.
avast, winmatrix forums and wincustomize forums and gmail.
Yes there was a registry problem few days earlier with 'Stop Error code c000021a' when I had installed ubericon 1.0.4 and iColorfolder. I mentioned it here https://forums.wincustomize.com/345931
But I had restored the whole disk image after that. So there should not be a single trace of it left.
I looked the processes at startup. The only dangerous is this...

But its Intel-manufactured. Should I disable it?
hardware connections was not reseated properly upon reassembly
Might be true. He claimed to be an expert but I suspect. I asked him to please read the service manual. He said "Boy, I know everything." He gave my laptop three scratches on cover. I didn't say him anything for that though.
Also when he reassembled everything there were two screws left. When I asked from where these screws came he said " These screws are mine."
I said " But they look like mine, please sir don't play with my laptop like a toy and place these screws at the proper place"
He said " Comon trust me nothing will happen"
I said "No I have to move it here and there. I can't lose two screws"
He said "Do you want me to reopen your laptop"
I said "What can I do? I have brought my laptop to remove the dust not the SCREWS"
He said "Alright I will do"
I said "thanks"
Then he removed the keyboard, looked if the screws were missing, then he looked down and wverywhere. At last he opened HDD. Alas! the screws belonged to there.
What a funny engineer "I know everything!" huh.
"Jack of LOL trades"