Im having the exact same problem as this guy
http://expertanswercenter.techtarget.com/eac/knowledgebaseAnswer/0,295199,sid63_gci973120,00.html
I cant get it to delete the partition... I tried to do the format thing and it wouldnt dimount... Do I need some kind of thing to wipe the partitions like the guy recomends? Is there any free program to do it?
It sounds like that guy is trying to delete his Windows partition from within Windows - not gonna happen. Do you get that error (or some kind of error regarding not being able to delete the partition) after booting from the Windows CD, accepting the license agreement, letting it search for existing installations, etc.? I've only had that happen personally when they're non-Windows partitions. Just curious - could it be a 'recovery' partition provided by a hardware manufacturer like IBM or Dell to allow you to quickly recover the system to the delivered state?
Anyway - basically you need an alternate method to delete the partition(s). fdisk running on a DOS disk will likely do the trick. I usually just throw a Linux build CD in the machine and pretend I'm going to install Linux since it lets me easily take good control of partitions with Disk Druid.
Start by grabbing a DOS disk with fdisk and see if that does the trick. If not, you can download a boot CD with any number of utilities that can take control over the situation.
And don't bother creating Windows start CDs (the set of 3 to 6 disks). That's only a workaround intended for systems that can't boot from CD and it will either work or fail in exactly the same way that booting from the CD does.
- Jason