While I find it good enough to remove all partitions and then boot the Windows install DVD, there are some versions of Windows that can't handle drives over 64GB, 120GB or other.
You left out major details so for now, just try wiping the drive with the maker's tools.
Ok, first off I was having problems with my pc and since I couldn't get it to boot, I took out the hard drive and attached it to another pc hoping to clear it and get a fresh install of a new but not Windows type OS. Well I thought I had done everything right by using Unetbootin to download the iso file of Zorin straight to my hard drive but when I go to put it in my pc I get the NTLDR is missing message. I tried to download a boot repair disk to a USB memory stick and then tried to reboot and still same error. Can someone please help me solve my problem; I have been at this for 2 days with no luck?