Summary
With the Digital River links no longer functional, which you used to download an .ISO file used for creating an installation DVD or USB Flash drive to re-install Windows 7 you are now left with two options.
Details
Revised: 03/02/15, 03/03/15, 09/18/16 and 01/16/17
1) Enter your “Retail” 25 character Windows 7 product key using the link listed here to obtain a .ISO file.
Microsoft's Software Download web page:
https://www.microsoft.com/en-us/software-download/home
Please note that OEM product keys for versions of Windows that came “pre-installed” and supplied by the computer manufacture may not work using the link listed above. Also not all "Retail" keys may fetch/list the proper language for the product key you entered (Only 2 of 3 key I entered returned the proper "English" language option).
If you experience this issue then try the following alternative:
Microsoft Windows and Office ISO Download Tool - HeiDoc.net
2) Burning a Windows 7 ISO File on a DVD:
https://support.microsoft.com/en-us/kb/977640 (Link no longer valid !
Use your .ISO file to create a bootable Windows installation DVD:
http://www.imgburn.com/index.php?act=download
In addition to supporting the creation of CDs/DVDs from .ISO files,
it supports a wide range of other image file formats, and it's free.
(BIN, CUE, DI, DVD, GI, IMG, MDS, NRG, PDI and ISO)
User Guide: Burning ISO Images with ImgBurn article:
http://neosmart.net/wiki/burning-iso-images-with-imgburn/
Rufus: Create bootable USB drives the easy way
3) If you purchased your software from a system builder who is no longer in business:
Media Replacement for End Users of System Builders
This website is to be used by End Users to acquire replacement media in the event that Microsoft software CD(s) originally purchased through a System Builder is defective, damaged on receipt or during installation, or misplaced. Additionally, an End User should only place orders through this website when they are not able to obtain replacement through the System Builder from whom they originally purchased the software.
Microsoft will replace one version of originally purchased software with one genuine OEM version of the same software.
There will be a charge of VAT for each product purchased.
If you purchased your software from a system builder who is no longer in business, click the link for your region in the following list:
Europe, Middle East, and Africa
https://om.one.microsoft.com/opa/start.om?StoreID=30B288C0-52A6-4AA4-A2BC-2B60DDA37DB1&NewTrans=1
United States and Canada
https://om.one.microsoft.com/opa/start.om?StoreID=B19F4CE9-DFCB-44E4-9ABE-1C9DFBAD47D0&NewTrans=1
Latin America or South America
https://om.one.microsoft.com/opa/start.om?StoreID=733F8F42-707E-4045-9243-A5E655A6041B&NewTrans=1
Asia-Pacific
https://om.one.microsoft.com/opa/start.om?StoreID=3D264FB4-A497-4C00-8180-2BB3C548B55B&NewTrans=1
4) Contact the computer manufacture to obtain replacement media.
Have your make, model number, serial number / service tag number ready when asked to provide the necessary information to obtain the correct media.
Note: there may be a small fee to cover the media cost or shipping charges.
List of support web site by manufacture:
Acer:
Acer support: http://www.acer.com/worldwide/support/
Acer Recovery Media: http://store.acer.com/store/aceramer/en_US/eRecovery
Advent:
Support: http://www.adventcomputers.co.uk/product-support/support-services
Alienware:
Support:
http://support.alienware.com/Support_Pages/contact_support.aspx
(US, UK and International)
Asus:
ASUS Support: http://support.asus.com/contactus.aspx?SLanguage=en
Dell:
Dell Support: http://www.dell.com/support/home/us/en/19?c=&l=&s=
or: Dell International Support Services:
http://www.dell.com/support/contents/us/en/19/category/Contact-Information/International-Support-Services
Emachines:
Support: http://www.emachines.com/ec/en/US/content/support
Fujitsu:
Support: http://www.fujitsu.com/global/support/
Gateway:
Support: http://www.gateway.com/worldwide/support/
HP:
Support: http://www8.hp.com/us/en/contact-hp/ww-contact-us.html
Lenovo:
Support: http://support.lenovo.com/en/supportphonelist
LG:
Support: http://www.lg.com/
Packard Bell:
Support: http://www.packardbell.com/index.html
Samsung:
Support: http://www.samsung.com/
Sony:
Support: http://www.sony.net/SonyInfo/Support/
Toshiba:
Support: http://www.toshiba.co.jp/worldwide/
4) If you have a friend with a "Retail" version (Full or Upgrade media) of the installation DVD (must be the same as your key was for: Home Premium, Pro or Ultimate) it will work with your "Retail" or "OEM" product key.