i am unable to install windows 8 RTM as a secondary OS on my desktop.

1. Post a screenshot of Disk Management so that all disks and partitions are visible.
2. On elevated command prompt type:
diskpart
list disk
Post printout of "list disk".

and this is the ERROR msg:

It is strange that 450 GB disk is listed in Win 7 first and when installing win 8 as second.
Put 450 GB disk first in BIOS.
Then in Win 7 delete the logical partition where you want to install Win 8.
Reboot with install DVD and let Windows 8 allocate and format the freed space on disk 2.

Windows always wants to put its boot files on first disk, active partition !
Boot files cannot go to second disk and a logical partition.

it is because of the SATA connectors on mother board. connectors are connected on the board in this arrangement i had 320 GB first on computer where i installed Win 7 about an year and half ago and then later i added an other Disk 500 GB. active Partition is still Where Windows 7 is installed and i ve tried to install Windows 8 on the same disk where the Win 7 is already running but of no avail.
repartitioning the disks and rearranging them would definitely solve the problem but i want to avoid this mess.

Now even after changing the connectors and putting the OS disk as first Disk i m unable to install Windows 8 and the ERROR is also same

You can download and install PartitionGuru (free) and use Menu - Tools - Check Partition Table
on both disks to see if disk structure is correct.

When installing you could go to advanced options and delete the partition in question and create again as primary.
Maybe this would help.

Prob solved and to b honest dont know y and how. I switched the SATA connectors back as were before on motherboard(when actually problem started) upon turning the power on i hit F2 to enter set up it generated error that CMOS date/time is incorrect(it was as BIOS is reset but i didn't reset the BIOS) anyways upon setting the date/time to current i booted the system with DVD for the first time it asked me hit any key to start from DVD(it never asked before since i m trying to install Win8) started the setup amd it worked...
Thank u very much for ur concern and support. Thnx alot

qaysy said:

generated error that CMOS date/time is incorrect(it was as BIOS is reset but i didn't reset the BIOS) anyways upon setting the date/time to current

Click to expand...

It could be your cmos battery is going flat, or you may have bumped it changing your SATA cables around. If you suddenly start having weird problems, or dropping time, be sure to check the battery. just some thing to keep an eye on. i'm glad you found your problem.

Yeah sure n thnx
Glad to b among such good knowledgeable people and such a wonderful Forum.