Windows 8.1 & Windows Server 2012 R2 - RTM released!

Make sure your .ISO file is untouched file, check SHA before you install :) 
Please note Windows 8.1 RTM build number is 9600.16384.130821-1623 

Windows 8.1

Windows 8.1 (multiple editions) (x86) - DVD (English-United Kingdom)

• File Name: en-gb_windows_8_1_x86_dvd.iso
• Filesize: 2785 MB; 2.71 GB (2,919,948,288 bytes)
• Languages: English
• SHA1: 7CD38ECE3D86339BC0BFEF4D4FAC6C5975248383

Windows 8.1 (multiple editions) (x86) - DVD (English)

• File Name: en_windows_8_1_x86_dvd.iso
• Filesize: 2780 MB; 2.71 GB (2,915,131,392 bytes)
• Languages: English
• SHA1: 802CFCD3A411D99C097EA7E747F0B6697F9BDAC4

Windows 8.1 (multiple editions) (x64) - DVD (English-United Kingdom)

• File Name: en-gb_windows_8_1_x64_dvd.iso
• Filesize: 3723 MB; 3.63 GB (3,904,124,928 bytes)
• Languages: English
• SHA1: 42458E48CECEBAB8BF5D58220478FDA42B0D2990

Windows 8.1 (multiple editions) (x64) - DVD (English)

• File Name: en_windows_8_1_x64_dvd.iso
• Filesize: 3719 MB; 3.63 GB (3,899,295,744 bytes)
• Languages: English
• SHA1: BC2F7FF5C91C9F0F8676E39E703085C65072139B

Windows 8.1 N (multiple editions) (x64) - DVD (English)

• File Name: en_windows_8_1_n_x64_dvd.iso
• Filesize: 3537 MB
• Languages: English
• SHA1: C1E1A2BA32598BBA3EE21A28AC4144462CBFF3D7

Windows 8.1 N (multiple editions) (x86) - DVD (English-United Kingdom)

• File Name: en-gb_windows_8_1_n_x86_dvd.iso
• Filesize: 2648 MB
• Languages: English
• SHA1: 03BE21817B8EC1464E4AC8F23A65723FD2FD5675

Windows 8.1 N (multiple editions) (x86) - DVD (English)

• File Name: en_windows_8_1_n_x86_dvd.iso
• Filesize: 2643 MB
• Languages: English
• SHA1: 76A587D6B5C7939FE72878253DAE50FEC698D2A9

Windows Server 2012 R2

Windows Server 2012 R2 (x64) - DVD (English)

• File Name: en_windows_server_2012_r2_x64_dvd.iso
• Filesize: 4071 MB
• Languages: English
• SHA1: B6F063436056510357CB19CB77DB781ED9C11DF3

Microsoft Hyper-V Server 2012 R2 (x64) - DVD (English)

• File Name: en_microsoft_hyper-v_server_2012_r2_x64_dvd.iso
• Filesize: 1917 MB
• Languages: English
• SHA1: 1EEC2EE8DD77E8EB970B210C9B0E01986D7210DD

Windows Storage Server 2012 R2 and Windows Server 2012 R2 Foundation (x64) - DVD (English)

• File Name: en_windows_storage_server_2012_r2_and_windows_server_2012_r2_foundation_x64_dvd.iso
• Filesize: 3860 MB
• Languages: English
• SHA1: E3F320EACACFC7F2B000D3E6B02872133BCA547C

source:  http://windowsforum.com/threads/windows-8-1-rtm-now-available-for-download.176800/