If you wish to disable local password caching (i.e. prevent creation of pwl files) use this registry key in Win9x. If you set this during logon it will become effective on the next logon.

code:
Registry Settings 
System Key: [HKEY_LOCAL_MACHINE\Network\Logon]
Value Name: NoDomainPwdCaching
Data Type: REG_DWORD (DWORD Value)
Value Data: (0 = disabled, 1 = enabled)

For deletion, just delete all *.pwl files during logon.

After doing this, they should not come back any more.
_________________________
Jack