Yes, SQl Server 7 will definitely work fine under Windows 2000 Prof. But if you use SQl Server 2000, then see that you use "Personal Edition" on Win 2000 Prof. Because Standard Edition and other editions need Win 2000 Server or Win NT.
Also, note that if you install SQL Server 7 on Win 2000 Prof, you have to have "NT Authentication".
regards,
Rohit.