How's it going.Let me read of your question. Give me a minute.
What is happening when you try to boot windows? Black screen? Error messages?
Can you boot into the BIOS?
Were was the Linux VM created as you said you could not get into Windows?
So you have Windows and Ubuntu dual booted?
You said the following. No mention of BIOS problems:
"So.. when i put USB bootable of win 7 , setup is loading .. then when install it says it couldnt find any driver , i thought its about USB 3.0 , i used then USB 2.0 , but still same problem .. then i created a virtual box in UBUNTU GNOME , to try install win7 there .. still error " You cant install virtualisation , check BIOS settings " . "
Please tell me:
You should not go in via GRUB. You need to go directly into the bios not through the kernel.
Are you on a hard-drive or laptop?
What the PC model?
Can you press the FN key when this is happening?