How to remove permanently the frozen state status in BIOS for optiplex GX620 :
Change the SATA Operation from Normal to Combination by doing the following steps:
1) Boot the Machine
2) Press F2 (before the progress bar completes)
3) Use the Up/Down Arrows on keyboard to select the Drives node
4) Press Enter on keyboard to expand the Drives node
5) Use the Up/Down Arrows on keyboard to select the SATA Operation node
6) Press Enter on the keyboard to make changes to the SATA Operation
7) Use the Left/Right Arrows on the keyboard to select Combination

Press Enter on the keyboard to choose the Combination setting
9) Press Esc on the keyboard
10) Use the Left/Right Arrows on the keyboard to select Exit
11) Press Enter on the keyboard
I tried this but it had no effect. The only way I found of clearing it was to remove the CMOS battery for a minute or two. Trouble is after reboot it comes back. So I am left wondering, is my hard drive ok?