Windows 7 reinstall

[megaboy1]

Hi.

I'm trying to re-install Windows 7 from Ultimate to Home premium. (Clean Install)
I have 3 physical hard drives.
And in 1 physical drive, there is windows installed as one logic drive and another separate logic drive contains pure personal data.
Is there any way to clean-install without affecting the data logic drive?

 

[Tmagic650]

When you start the Windows 7 custom install, you should see a list of partitions available. Select the Windows 7 Ultimate partition, open disk options and delete it. Start the clean Windows install on that un-allocated (former Windows 7 Ultimate) partition