After the partition table is destroyed, the system will warn you with "Non-System disk or disk error, replace disk and press a key to reboot "and "Error Loading Operating System "or "No ROM Basic, System Halted". So how could these things happen?
1. Error caused by virus.
Computer virus is the main cause that leads to partition table damages. Take CIH virus and its variations. This kind of virus can attack BIOS and destroy partition table. And some boot virus can also destroy partition table.
2. Environment reasons
The current Windows XP/2000 cannot support NTFS file systems, while the system will be installed with NTFS file system as default. It while converting to NTFS file systems, the process is interrupted by a power failure or a response failure, the partition table would be destroyed. What's more, the partition table is at risk when you performing partition management with partition software. If the computer fails to response, or the power fails, the partition table would be destroyed and data would be lost.
3. Improper operations
If there are multiple systems on hard disk, partition table error could occur when uninstall one of the systems. For example, if you uninstall Windows 2000 from the computer with Windows 98 and 2000 installed, server partition table error could occur. Moreover, drive letter would be unreadable when you delete the primary partitions without deleting extended partitions.
How to recover partition table?
Recover partition table with Fdisk command.
Fdisk is not only a partition program but also has the function of recover primary boot sector. It can only change primary boot sector. Thus, it is a very ideal tool for partition table recovery under Windows 9x systems. When recovering primary boot sector, you should boot Windows 98 from CD, and input Fdisk/mbr to cover the main boot record.
Tip: This command can only recover main partition table without restructuring it. So it can only be used to recover MBR if the MBR is destroyed by boot virus or data loss. Moreover, this command cannot be used to clear all boot viruses.
Restore MBR with the command Fixmbr
Under Windows 2000/Xp, we usually can use some commands to recover some system error or failure. Fixmbr can be used to recover or replace the MBR to fix drives. Fixboot can recover readable sector. Diskpart can create or delete partitions on hard disks. Expand can draw some lost files from the set CAB source files. Listsvc can create a server list show the current state of servers. Disable and enable can ban or let some services or devices. Help command can be used to check the clear explanation of some control command or to check all commands.
For instance, you can input command fixmbr and check the mbr of the current system, then input Y to confirm to write in a new MBR. This will complete the recovery of MBR
When deleting or creating partitions, any incidents such as a power failure or a response failure could lead to the disk partition table being unreadable by the current partition software. We can use a 3rd party partitioning software to recover the MBR. If we fail to partition hard disk with Fdisk command, we can use MiniTool Partition Manager to solve all the problems.
First, select the partition that needs to be recovered, and fix it.
All this process will be finished in a special protection mode. And this process will complete in minutes. You data is safe when using MiniTool Partition Manager, and you will no longer worry about data loss due to computer failures or power failures.
Some more advanced functions: rebuild MBR, convert DPT (disk partition table) format from MBR to GTP, and recover data, move/resize system partitions, convert file systems and much more.
MiniTool Partition Manager can support both MBR and GUID partition table format running on 32/64 bits Operating System including Windows XP, Vista, Windows Server 2000/2003/2008 and the latest Windows 7.