A unusual grub problem

[snowball]

Hi,all.
These day ,I met a problem.
One day,when I start my PC,I found it enter into a grub command line.Then I used the fdisk /mbr in dos to unintall grub.And then reinstall the Fc5 x86_64.After a few use ,I met the same problem. I did use the FC-5-x86_64-rescuecd.iso.And I found that /boot/grub/menu.lst was blank.
I have try some methods but it did't help.
=================================================
My Pc:
Mother Board:Onda 915PLD
Celeron 64-bit 2.93G
Radeon X550XT
Realtek AC'97
KingBox 512M
Seagate SATA 120G

[Dan]

I believe your HDD may be developing problems.

[snowball]

But I test my HDD with the tool named "HDDLife Pro" .My HDD is ok.
And my harddisk have't been used for a year.
I have use the Partition Magic to divided my harddisk in Windows.
Is that a matter?
Thanks.

[Dan]

Originally Posted by snowball

But I test my HDD with the tool named "HDDLife Pro" .My HDD is ok.
And my harddisk have't been used for a year.
I have use the Partition Magic to divided my harddisk in Windows.
Is that a matter?
Thanks.

Shouldn't have bothered anything. I don't know where to look next. I don't use 64 bit edition.

Dan