I installed a 100 GB hard drive in my new system and it reads as 100 GB under BIOS but Windows reads it as 4.87GB how can I get windows to recognize the full size of the hard drive?

Where is Windows reading it as 4.87GB or is that just the size of the C: drive?

Enter diskmgmt.msc into the run box and see how the drive is displayed/formatted/partitioned there.

it's reading 4.87 GB under properties in My Computer the drive is my H: drive my C: drive is fine

Check out what Disk Management sees.

ok never mind thanks for the info once I got into Disk Mgmt I found the problem windows partitioned out 4.87 GB for back up and left the other 95 GB unassigned so thanks again for all your help