Use free Partition Wizard bootable CD
to shrink C: smaller than J: then copy C: into deleted J: space, recover MBR into C:
Boot PW CD, select 1 for screen resolution, then rightclick C:, Resize smaller than J:, OK.
Now rightclick J: partition to Delete, OK. Now rightclick C: Copy into J: space, letter it C:, OK. Apply all steps.
Either swap the cable for DISK0 to DISK1, or set DISK1 as first HD to boot in BIOS boot order, after DVD. Leave DISK0 unplugged.
Now boot into Windows 7 DVD, select Repair console on second screen, click through to recovery tools to open a Command Line, type:
SELECT DISK # (# for new Windows 7 HD)
SELECT PARTITION # (# for Windows 7 partition)
Now boot back into Windows 7 DVD Repair console, click through to Recovery Tools, select Startup Repair and run up to 3 separate times with reboots to rewrite MBR to Windows 7 partition.
After Windows 7 starts, you can plug in other HD to delete using booted PW CD.