Dos command to recognise 40GB IDE Harddisk

Dear Sirs


We have a machine orignally with IDE Harddisk of 1.2GB, now we need to replace it with 40GB similar IDE Harddisk

This 40GB Harddisk is not getting recognised and we understand that there is a command in DOS, which will help to recognise this 40GB Harddisk by system

Command FDISK is also not working as Harddisk itself is not getting recognised, we had similar problem in our another machine and software expert told us about a command and by using that command, we could configure 40GB harddisk in place of 1.2GB then could install MSDOS 6.22 following by Windows Workgroup 3.1 and other OEM software

Kindly let us know about that command so that we can configure 40GB Harddisk in pace of 1.2GB

Warm Regards