How to Fix “Invalid System Disk” error ?

During the startup of the computer, you may receive the following error message:
“Invalid system disk
Replace the disk, and then press any key”

Typically, such an error message at PC boot might be caused when the computer may be infected with a boot-sector virus such as the AntiCMOS.A virus, or when there is a missing system file or hard disk error on the PC. After talking about how to fix Windows failure to start error, now I will show you how to fix the “Invalid system disk” error at PC boot.

Just as what I have ever said previously, an “Invalid system disk” error message will appear when the computer is infected by viruses. Viruses are able to attach and remove the exact files that are essential for your system and sometimes they will disguise themselves as the legitimate system files so as to do whatever they want on the computer. When your Windows computer cannot find the correct file to start up the computer, you will soon get the error message. To well protect your personal information and ensure a smooth computer startup all the time, you’d better download & install a professional antivirus antispyware program to thoroughly scan your whole PC and get rid of all computer viruses or malwares.

Sometimes, the “Invalid system disk” error at PC boot has something to do with the hard disk errors. Those errors will stop you from reading some files correctly and then display the startup error message. To get rid of it, you have to first check and fix all errors existing in your hard disk.

*Open Computer by clicking the Start button, and then Computer.
*Right-click the drive that you want to check, and click Properties.
*Click the Tools tab, and then, under Error-checking, click Check now. If you are asked for a an administrator password or confirmation, type the password or provide confirmation.

->To automatically repair any detected problems with files and folders, select “Automatically fix file system errors”. If not, the scan will not report errors on your hard disk without fixing them for you.
->To perform a thorough check, select “Scan for and attempt recovery of bad sectors”. This option helps to find and repair physical errors on your drive itself.
->To check for both file errors and physical errors, select the two options.
* Click Start and follow the on-screen steps to finish the scan and repair jobs.

Note: How long a hard disk error checking takes depends on the size of your drive. Be patient if it takes several minutes longer. To get faster, it is highly advised that you should not use the computer for any other tasks when it is checking for errors. Though these steps sound simple and easy, they help to get rid of “Invalid system disk” error instantly or some other errors like PSD runtime application error.

After the above processes, it is highly recommended that you should run a registry cleaner to scan and fix all errors that might be hidden in your system in order to fix the “Invalid system disk” startup error. No matter whenever you install a program on the computer, it will automatically add some entries into the registry database to ensure its correct running; however, all those entries won’t be always remove completely when you uninstall the programs from the computer, making the computer run improperly/stopping you from successfully installing other programs, etc.

According to my own experience, an error message like “Invalid system disk” at PC boot can be very annoying. However, you are able to instantly deal with it by easily performing the above steps and then get the computer to boot up properly.