Problem with OSR2 Install

I have made a blunder, partly my fault, partly the fault of a work colleague.  I was asked to install a new motherboard in a Micron Pentium 100 (a direct replacement), due to the failure of the external cache.  I was also given the Win95 install disks, which happened to be the OEM version of Win95 with FAT32.  Had I been paying attention, I would have realized that this operating system didn't go with this computer, obviously because of the age of the system.  However, before I caught my error, I had already begun installing the system.  Everything appeared to proceed normally, until the time for reboot, when the system tried to format the harddisk and locked up.

Since the system originally had FAT16 on it, the installation messed up the harddisk.  I tried to use the format command on the CD, after booting with the floppy, but it froze each time.  Eventually, I managed to format the disk by using DOS 6.22.  It hung at 66% but then slowly proceeded to finish.  I then installed DOS and Win3.11, which appear to run fine.  
The problem is that the HD is now reported as 1.2 GB, although it is actually 850MB.  The bios is set correctly and auto recognizes the disk.  I am afraid to upgrade to Win95 at this point.  I have Partition Magic and wonder if it might straighten out the problem (perhaps a cluster size prob. or FAT prob?)  
Any ideas?  Thanks.