BIOS time and settings resets
If you find that you are continually resetting the system time, it could be that the CMOS battery is dying. In the absence of an external time source, the time in the BIOS is where the system gets its cue for date and time. Change the CMOS battery and the problem should be solved.
Attempts to boot to incorrect device
When multiple volumes or partitions exist on the computer, or there are multiple hard drives and maybe CD/DVD drives as well, there are multiple potential sources for the boot files. If the system delivers and “operating system not found” messages, it could be that the system is looking in the wrong location for the boot files.
The boot order is set in the BIOS. Check the boot order and ensure that it is set to boot to the partition, volume, and hard drive where the boot files are located. One thing that you should always check first is if there is no CD/DVD in the CD/DVD drive. When the system is running down the list of potential sources of boot files, in all other cases if it looks in a location and finds no boot files it will move on to the next location in the list. However, if a CD/DVD is in the CD/DVD drive and it checks the CD/DVD drive and no boot files are present, it does not proceed but stops and issues the non system disk message.
Boot problems can also occur with corruption of the boot files or missing components (such as the NTLDR file being “accidently” deleted by an overzealous user). Lockily, during the installation fo the OS, log file are created in the %SystemRoot% or %SystemRoot%\Debug folder (C:\Windows\Debug, depending on the operating system). If you have a puzzling problem, look at these logs to see if you can find error entries there. These are primarily helpful during installation. For routine troubleshooting, you can activate boot logging by selecting Enable Boot Logging from the Windows Advanced Options menu to create an ntbtlog.txt log file in the %Systemroot% folder.
If the system reboots on its own, consider the following possibilities:
- Electrical problems such as brownouts (not a total loss of power but a sag in the power level) or blackouts can cause reboots.
- Power supply problems can cause reboots as well. The power supply continually sends a Power_Good signal to the motherboard and if this signal is not present momentarily the system will reset.
- Overheating is also a big cause of reboots. When CPUs get overheated, a cycle of reboots can ensue. Make sure the fan is working on the heat sink and the system fan is also working. If required, vacuum the dust from around the vents.
Slow System Performance
Slow system performance can come from many issues. For the purpose of this discussion, we are going to focus on performance that deteriorates after being acceptable as opposed to system performance that is poor from the outset (which could be a matter of insufficient resources such as RAM). Here is a list of possibilities:
- The first thing to check is the presence of a virus. If the system seems to have an overabundance of disk activity, scan it for viruses, using a virus program that resides externally on a CD/DVD or memory stick.
- Defragment the hard drive. The more fragmented it is, the slower the disk access will be.
- Check the space on the hard drive. When the partition or volume where the operating system is located becomes full, performance will suffer. This is why it is good idea to store data and application on a different partition from that holding the system files.
- Ensure the latest updates are installed. In many cases, updates help to solve performance problems so make sure they are current.
Boots to Safe Mode
In many cases a system will no boot in regular mode but will do so in Safe Mode. Safe Mode loads the operating system but none of the drivers, with the exception of those absolutely essential to the system and those required for use of the keyboard, mouse, and the basic display (VGA mode)
If the system will start in Safe Mode but not otherwise, it is most likely a bad driver that is causing the System Restore procedure to a point in time before the driver problem occurred. You can also use the Roll Back Driver feature to revert back to the older but functional driver as well. The problem with this approach is that you have no identified the problem driver and the issue may emerge again later.
If you go to Device Manager and check the status of all the devices, you should see a device that has a problem. Try updating the driver; that may be better long-term solution. Another option is to look in the system log in Event Viewer and the problem driver may be specified in a message there as well.