Test Bed :
An execution environment configured for testing. May 
consist of specific hardware, OS, network topology, 
configuration of the product under test, other application 
or system software.

Test Environment :
The hardware and software environment in which tests will 
be run, and any other software with which the software 
under test interacts when under test including stubs and 
test drivers.

test bed means an environment that contain the integrated 
hardware,instrumentation,simulator,software tools,and other 
support elements needed to conduct a test of a logical or 
physically separated components.
A suite of test program used in conducting the test of a 
component or system.     


Test environment means with all possible and required 
component in which that s/w is expected to work in 
production.