How to install a new operating system??

A friend accidentally deleted some Win 98 SE files from his computer. Then the hard disk was formatted. When I tried to install Win ME for him, the system responded “unable to distribute conventional memory, please restart the computer and release some conventional memory..”
However, the config.sys file is no longer in the hard disk. There are only three files now – config.win ; setuplog.txt and setuplog.old
Right now the system cannot start from the hard disk.
What should be done to solve the problem?
This is urgent! Any help is highly appreciated!
Thanks in advance!