Dell Inspiron 1545 not booting

I have had this computer for almost 3 years now and have had no problems with the hardware before. I went to start my laptop earlier this week and it keeps loading without coming to my screen where I enter my password to go onto my desktop. It returns to an error message after trying to load with no success. The message says:

Windows failed to start.A recent hardware or software change might be the cause. To fix the problem:
Insert windows installation disk and restart.

Then it asks me to choose a mode: Safe mode, etc.

What's wrong with it and why am I getting this message?

Any help would be highly appreciated. Thanks!
 
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