HDD Question

AIV said:

If i buy new internal hard disk, unplug the old one, and install windows 7 to the new one, what will happen to the old one, will it lose data or just system data???

All the data will be still on it plug it in as a secondary HDD, get the into you want to keep off it then format the drive then putt everything you want backed up in the secondary HDD.

It won't boot, but you should be able to read all the files. You will probably have to take ownership (Take Ownership Shortcut) of some files or folders to allow access as they will retain permissions for the previous user (your ID in the old OS). If you want to be able to boot the old drive, you should be able to by making it the default boot drive in the bios or we may be able to add it to the boot choices. If you want to be able to boot both drives a dual install may be better/easier. Dual Boot Installation with Windows 7 and Vista (if not Vista, see the related links for other OS's).

First, nothing can physically happen to the data on the first drive if it's not plugged in.

After you install Win7 and re-plug in the older drive, you may need to take ownership of the files on that older drive, but tha's an easy thing to do.