Cold shutdown, sudden system-related shutdowns could lead to bootdrive hanging at start. If the problem is not severe(lacking or damaged files) one could try to repair like this.
I remembered in earlier days of Win2k and IDE-drives only when such a Fail-drive is attached as slave and PC bootet it will be automatically repaired.IN newer PCs like my Universal IDE-SATA-MOBOs i simply attach drive to second channel. didnt yet test third one.
Other success-stories were:
1. Cleaning contacts-should be done anyway regularly
2. removing battery remove power, press power button on pc to uncharge.

If these fail the solution is attaching failing drive to a working system(same OS-Here Winxp and the same MOBO)
Then doing a drive-error-cleaning.
Such success stories arae the reason why i dont give up lame old PCS. it could help to solve problems on newer ones.