This works:

SELECT * INTO TEMP from Tbl1 ORDER BY Code;
ALTER TABLE TEMP ADD C Autoinc;
update temp set Code = C;
alter table temp drop c;
delete from Tbl1;
insert into Tbl1 select * from temp;

This doesn't:

SELECT * INTO "\Memory\TEMP" from Tbl1 ORDER BY Code;
ALTER TABLE "\Memory\TEMP" ADD C Autoinc;
update "\Memory\TEMP" set Code = C;
alter table "\Memory\TEMP" drop c;
delete from Tbl1;
insert into Tbl1 select * from "\Memory\TEMP";

---

 Comments

---

The problem was caused by the engine trying to store the temporary table used in the table alteration on disk instead of in-memory. When the process is done, it would try to rename the disk table to an in-memory table, which the operating system choked on, of course.

---

 Resolution

---

Fixed Problem on 3/13/2004 in version 4.05 build 1