Dell Inspiron 620 Won't Load Windows.

I purchased a used 620 on eBay that was working perfectly except the wi-fi connection.  After trying all I knew or read about with no success, I tried to connect via an ethernet cable to a connected laptop i own.  The 620 crashed and freezes when it tries to load Windows.  I tried to boot from a flash drive to update the CMOS, but it said I had  missing or corrupted Himem and Ramdisk system files.  I had just gotten this computer and did not do a recovery cd when I should have.  Is there anything I can do?  I don't have any disks to fix or reload Windows.  I would be eternally grateful if someone could help.