I made the ISO from the Digital River download files, but I had trouble making a bootable DVD from it. The following worked for me.
If you don't already have them, download and install ImgBurn, and Daemon Tools Lite.
1. Open ImgBurn, and select "Write files/folders to disk"
2. Insert blank disk in burner, and wait for status to become ready.
3. Mount the W7 iso with Daemon Tools Lite, and open it in Explorer.
4. Select the sourse in the ImgBurn Source box.
5. Select the Advanced tab, and go to the Bootable Disk tab in ImgBurn.
6. Check the "Make Image Bootable" box in "Options"
7. Bootable Disk tab;
Emulation Type = None (Custom)
Boot Image = (sourse drive letter)-\boot\etfsboot.com
Developer ID field = Microsoft Corporation
Load Segment field = 07C0
Sectors To Load = 8 (Value is twice the size- in KB- of the image file. etfsboot.com = 4KB.)
8. Click the icon in the bottom left of ImgBurn to start writing to disk.
9. If prompted, click "Yes" to switch to UDF from ISO9660 + UDF.
10. When prompted, click "Yes" to accept the Volume Lable.
11. Click OK to confirm the configuration on the next popup.