>ORADIM -NEW -ASMSID asm10 -SYSPWD nevertell -PFILE C:\oracle\admin\asm10\pfile\initasm10.ora
Instance created.

>set oracle_sid=asm10

>sqlplus /nolog

SQL*Plus: Release 10....
Copyright (c) 1982, 2004, Oracle.  All rights reserved.

SQL> CONNECT system/nevertell AS SYSDBA
Connected to an idle instance.

SQL> STARTUP PFILE='C:\oracle\admin\asm10\pfile\initasm10.ora';
ASM instance started

Total System Global Area    125829120 bytes
Fixed Size                    769268 bytes
Variable Size               125059852 bytes
Database Buffers                   0 bytes
Redo Buffers                       0 bytes
ORA-15110: no diskgroups mounted 

SQL> CREATE SPFILE FROM PFILE='C:\oracle\admin\asm10\pfile\initasm10.ora';
File created.

SQL> SHUTDOWN
ASM instance shutdown

SQL> STARTUP
ASM instance started
...