I think the HDD was faulty since long, and it was somehow carrying forward.
Today when the engineer came, he also was completely puzzled on seeing the situation
Windows was in. Even if someone r***s Windows, it cant get this bad!! (He didnt say that, but the look on his face said that!)
When he finally started to format, first he tried with Windows 7. The Drive C got formatted, but then when installation started, it gave some error that installation cud not proceed.
Then he tried XP. He again formatted that partition to be safe. That formatting took 45 minutes. And after that, when Windows restarted to carry on with install, it gave a Blue Screen of Death twice. In short even XP didnt install on that partition.
So finally he said that its better we format the whole HDD......for that i had to take a backup of all my data, without any sort of Working OS on my PC!! Coz Windows had already dozed off, and even Grub didnt appear, so no Mint either.
I had to download the whole OS from the other PC, & make a Live session out of it. While that happened i got an External HDD, which was already due.
In short, data is getting backed up now, and tomorrow the thorough formatting will take place hopefully!
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Oh & 1 more thing. I wanted to try out Mint 11 since long......but i didnt expect i will be running it in this manner!!