TEST ENVIRONMENT: This is the Hardware,Software platforms 
to be employed for the testing which is of the same quality 
of the production environment.

TEST BED: It also includes Test environment along with the 
infra structures,data guidelines,etc..

DATA BED: It is the range of values which can be given as 
input while testing.

TEST DATA: This is the data which we are giving as input 
while testing.

If Im wrong plz mail me!!!

Test Environment: The hardware and software environment in 
which tests will be run.

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, etc. The Test Plan for a project should 
enumerated the test beds(s) to be used. 

Test data: All the inputs used for our testing like 
Testplan,Project Plan,Testcase documents,Input data and the 
other testing related documents.

Please correct me,if I am wrong.

As per the Bs-7925-1 Testing Termonology

Test Bed Definition and Test Environment Definition are 
Same.

Supporting items which are used to Conduct Test.

test environmnt: Required S.W and H.W
test bed:Required documents to be applied on build to 
validate functionality.