(Attock VU Group) need urgent help ........

i am using assembly language programming in window 7 64 bit. DOX BOX is also installed. 

i am able to write the hello world program successfully.

created .asm, .com and .lst files

also successful in creating obj file.

now the problem is "i am not able to print hello world on screen.

whenever giving the command "ld" i.e. ld hello.o -o hello.exe", its not working. 

i am getting an error "ld is not recognized as external or internal command, operational program or batch file"

pls help me and tell me how to print hello world on screen

i will be very thankful

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