Error: usbtest(Cs).exe----cannt find DLL

Dear, I released my c# project usbtest(Cs) and got the usbtest(Cs).exe.There is no problem when I run it on my own WinXP PC,but when I run it on other's WinXP PC or Win2000 PC,then error occurs: Win2000:error name:usbtest(Cs).exe--cannot find DLL error content:can not find DLL mscoree.dll in the appointed path. F:\;.;C:\WINNT\System32; C:\WINNT\system; C:\WINNT;C:\WINNT\system32;C:\WINNT;C:\WINNT\System32\Wbem WinXP: error name:usbtest(Cs).exe--application error error content:application normal initialization (0xc0000135) fail.Please click "OK" to terminate application. Can you tell what makes this error and how to work out it? Thanks! momer