I have a Vostro 1500 laptop. It worked fine at noon and I left it only and plugged in to use later in the day like I have MANY times. However, when I came back to use it later, it did not work. It attempts to boot up but does not make it any further than the sign-in screen then it reboots again. I did a few tests on it and I received 2 error codes. They are 0148 & 0123. Any ideas on what has happened or what these codes mean? Any help would be greatly appreciated!
Presumably these occurred during the hard drive test and were preceded by 1000: or 2000:? If so, they mean the hard drive has developed bad sectors and needs to be replaced.
Yes, they were both preceded by 2000. Is there a way to know for sure or to somehow get it to start despite the issues?
You can be sure the drive is on its way to duty as a paperweight - it is failing. It is unlikely you'll get Windows to boot - and you should not even try unless you can afford to lose everything on the drive.
If you need to recover data from the drive, proceed as follows:
Replace the drive with a new 2.5" 9.5 mm SATA notebook hard drive. Reload everything and mount the dying drive in a 2.5" USB 2.0 case ($10-20; newegg.com has many) and attach it to the restored system. You can likely recover some or all of your data simply by copying it to the new drive.