New
#11
I am not sure how you lost your Vista boot if you never installed anything. Unless it was the changes you made in BIOS.
Go into BIOS and set back to defaults. Make sure DVD drive is set to boot first, then HD.
Also check SATA controller to see if it is set to AHCI.
Now boot into Win7 DVD and see if it shows partitions for install after you select Custom.
If not then we need to put your SATA controller driver into installer at the bottom left link on that Custom partition selection screen.
Better fill in your System Specs in bottom left of post.