The question. Can external hard drives interfere with the boot process of Vista 64 bits home premium edition.
I have a confusing intermittent boot problem on a Dell Studio 540 computer that has the very latest version of Vista home premium 64 bits and the latest drivers from Dell. I bought the computer from Best Buy in January. (Came with 2 hard drives of 600 G each in a striped RAID array, so as to appear as a single large drive.) After a few weeks of use, I began to get an intermittent error while starting the computer or rebooting. After the computer bios had done its thing, I would get a black screen with the error message "error loading os." The errors gradually became more frequent. These error messages appeared before Vista started to load.
A best buy technician took control of my computer over the Internet and verified that the problems were not caused by virus, adware or other malware. He ran a program that reported problems with Vista program files. He had me restart the computer and run checkdisk with the repair option on. Then I opened the command prompt and ran sfc /scannow. The latter program reported that there were errors within an obsolete printer file that had been installed during a failed installation of a HP printer that was not adequately supported under the Vista 64-bit system. The program also reported errors within files for the Vista sidebar and reported that none of the errors for the printer file or they sidebar could be fixed. As befits a Microsoft-based product the error messages of course were actually contradictory. On the black command prompt screen would be a message stating that "Windows resource protection found corrupt files but was unable to fix some of them." "Details are included in the CBS.log." That log reported the names of the files that could not be fixed, stated that they could not be fixed, but then at the very end reported that all problems have been fixed. Each time I ran the sfc program, I got the same contradictory error messages.
I used a disk that came with the computer to reinstall Windows Vista -- this did not reformat the RAID array hard drives but rather moved the Windows files into a new folder and reinstalled Windows and left my data intact on the hard drives. Things worked perfectly afterwards. I reinstalled my programs and began work. I got a lot of work done.
However, last week I plugged in a USB drive that had been temporarily disconnected. I then got a message in Windows that said changes had been made and that I should reboot. The message did not explain what changes had been made. When I rebooted, I got the familiar black screen with the error message "error loading os." I tried repeatedly rebooting, tried leaving the machine off for a minute or so, unplugged the power cord from it well was off. (The one thing I did not do was to hold down the power key for several seconds while the computer was unplugged -- according to an online manual this completely drains the motherboard of power but I did not know that then.) After about 15 or 20 attempts at rebooting the computer booted up normally. When I looked in the events log for administrators I found that Vista reported that 2 hard drives had the same signature and that it had changed the signature on one of them. That change occurred just before I tried to reboot after reading the Vista message about changes having been made.
Best Buy will replace the hard drives, but that would mean having to reload all of my many hundreds of gigabytes of data. And I wonder if something else is going on other than problems with the hard drives. I've run the sfc program several times without finding any errors. I've tried rebooting the computer, and it does fine each time. I don't want to have Best Buy spend money replacing the hard drives nor do I want to have to reload data unless necessary.
Can USB drives interfere with the boot process? (I know that an external drive can interfere with the stability of Vista itself because I have a FireWire-based Maxtor external hard drive that has to be left connected to an XP-based computer in my home network. If it is connected directly to the Vista-based computer, that computer starts to have blue screens of death. Without the FireWire external hard drive being attached to the Vista computer, the computer never seems to crash. (I'm ashamed to say that I went through 2 new Gateway Vista-based computers that each kept giving blue screens of death. A Microsoft article claimed that the problem with FireWire-based external drives was fixed some time ago -- not true for the 2 Gateway computers that were returned to Best Buy and not true for my Dell. I did not catch on to what was happening until I started to read the administrator events log and found that each blue screen of death crash was preceded approximately 8 to 10 minutes by an error message stating that the FireWire drive had not responded promptly enough to queries by the computer. Every blue screen crash seemed to be preceded by this message. -- found this out on the Dell computer which seem to crash less often than those Gateway units)
Right now I'm not using the new Vista-based computer except for the purpose of repeatedly rebooting. My main use for it is to run Adobe Photoshop CS4 with 8 GB of RAM available. After I got the computer going following the booting problems last week I deactivated the program to avoid losing my license if the computer refused to boot again. The fact that the initial bout of errors were at first infrequent and then became more and more frequent suggest that the hard drives may gradually somehow fail. However, sfc has not reported a single problem since Vista was reinstalled.
Had the same problem (but I run XP not Vista), searched the Internet and found a million people with the same problem and a million helpful people and their "solutions" to the problem, of which some did just not work, and some were downright dangerous to the health of my PC. But at last I found a solution that works, and it's simple (thank you saykomatrixx):
First (of course) you check your BIOS to see that USB-devices are below (after) internal HD:s in the boot sequence, and that might be all you need to do.
If that does not work, or your BIOS (like mine) does not have this option (I only had Disk drives, Hard Drives, Network drives, and Floppy drives - apparently the USB device must be connected and on to show up here, which is just what it can't do), then here's the beauty:
Find (in BIOS) the "USB Legacy Support", make sure it is set to "Enabled", and voilà, it should work like a charm to start-up with the external HD:s connected and on.
I did get a small surprise during next start-up when Windows started to install drivers for my sound card, and later I had to change some settings in my sound card to get my microphone to work again, as the driver install had changed some settings there, but otherwise everything is just hunky dory.
I don't really know what the "USB Legacy Support" is/does (perhaps a more educated member could tell us?) but as my already was in "Auto" which is a sort of semi-on (software controlled is my guess), the difference can't be that huge from before I switched it fully on.