SupportAssist OS Recovery

My hard disk is partitioned into two partitions (C: OS and D: Data)

Can anyone advise if using Dell SupportAssist OS Recovery will revert the system back to one partition?

I do not need the second partition and have had no success in trying to format or unmount the partition in Disk Management! Seems there may be some system files there that I cannot delete, so will not allow me to remove the partition and share this space with the OS.

Hence the possible need to restore to factory settings and go for a clean install!

Any help is appreciated. Many thanks.