Symptoms
Restoring a database backup on Microsoft Windows 98 fails if all the following conditions are met:The file size of the restored database is 2 GB or greater.
The database is being restored over an existing database that is less than 2 GB even if there is more than 2 GBs of free disk space.Here is an example of the error message that might occur:

Server: Msg 3257, Level 16, State 1, Line 1
There is insufficient free space on disk volume ‘D:\MSSQL7\DATA’ to create the database. The database requires 2352873472 additional free bytes, while only 2147155968 bytes are available.
Server: Msg 3013, Level 16, State 1, Line 1
Backup or restore operation terminating abnormally.This error message occurred while attempting to restore a 2 GB database over a newly created or existing database that was less than 2 GB. The restored database file (.mdf) would have been 2,352,873,472 bytes in size.
Resolution
On Microsoft Windows 98, a different Win32 function is called to determine how much free space is available. The function that is called returns a maximum of 2 GB free space.
For additional information about the Win32 function, click the article number below to view the article in the Microsoft Knowledge Base:
231497?(http://support.microsoft.com/kb/231497/EN-US/) INF : Understanding and Using GetDiskFreeSpace and GetDiskFreeSpaceEx