Error: ORA-12705: Cannot access NLS data files or invalid environment specified

I have an OracleXE 11g instance on a remote server machine. Some developers who have Russian Windows 7 SP1 can't connect to it. They got this error message: ORA-12705: Cannot access NLS data files or invalid environment specified There is no error if you use enUS Windows 7 SP1 machine. I tried many ways to solve this: I checked language settings on server machine: ``` SELECT * FROM V$NLS_PARAMETERS; SELECT USERENV ('language') FROM DUAL; ``` Both returns GERMAN_GERMANY.AL32UTF8. I tried different ways to solve this issue by doing this: - Rename registry key NLS_LANG to NLS_LANGX on server machine. Did nothing. - Create NLS_LANG environment variable with value of GERMAN_GERMANY.AL32UTF8. - Control panel > Regional and language options > Format and set Russian there. None of this works. What should I do?