The general download of Windows 7 was removed when it was released to manufactures in August, I believe. You can still download the 90 Day Enterprise evaluation -=> Here
My Computer
At a glance
64-bit Windows 8.1 ProCore(TM) i5 CPU 4330 Haswell @ 3.20GHz12.00 GBIntel(R) HD Graphics
Computer type
PC/Desktop
Computer Manufacturer/Model Number
LENOVO K450 @3.0GHZ
OS
64-bit Windows 8.1 Pro
CPU
Core(TM) i5 CPU 4330 Haswell @ 3.20GHz
Motherboard
LENOVO
Memory
12.00 GB
Graphics Card(s)
Intel(R) HD Graphics
Sound Card
Intel HD integtrated
Monitor(s) Displays
HP 25' ISP Monitor
Screen Resolution
1900/1020
Hard Drives
(1) ST1000DM003-1CH162 (2) Generic STORAGE DEVICE USB Device (3) Generic STORAGE DEVICE USB Device
They also have a 90-day eval in VHD format at the following (for use on Windows Server 2008). This is different from the Enterprise eval which is directed at IT professionals: