Hi,
Do you have the Windows 95 install disks?
If so, you can download files from here:
http://www.bootdisk.com/bootdisk.htm
They can be used to make a floppy boot disk for Win95, and will allow you to get to the C:> promt. You can then format the hard drive, and re-install windows, but only if you have the install disks for 95.
When you say you deleted some windows operating files, you may not be able to re-install all the windows operating system files by just copying them back, without reinstalling windows.