The Invalid System Disk error can occur for a number of reasons. In most cases, this error occurs after an operating system install, reinstall, hard drive replacement or motherboard upgrade.
Start your PC by using the Windows Startup disk, and then use the sys command from the Windows Startup disk to restore the system files to the hard disk. Some systems use built-in anti-virus software that must be disabled in the computer's BIOS.
I know that a quick google search will give me a bazillion hits on this topic, but I am having one heck of a time trying to find anything that will help..
On of our employees brought in a HP Pavilion with Windows ME and I am getting the error "invalid system disk..." I made a bootdisk from bootdisk.com and have tried the much suggested sys C: only to get the "bad command" response. The disk has the sys.com file on it and I have ran scan disk.
The CD Rom driving is constantly turning and looking for something, but I'm not sure what.
Any ideas how to get this thing going?