Why do you suspect a hardware failure? The fact that it's booting to the Windows flag screen suggest that the hardware for the most part is working just fine... What is happening is the software is probably jacked up, and crashing behind that splash screen...
How long have you let it sit there? I have had computers in the past get stuck on that screen for 10-15 minutes (or even longer) and then all the sudden continue booting...
Try Safe Mode and see if that boots, roll back to a restore point or simply reinstall Windows...
BTW if you do go to a reinstall I HIGHLY suggest doing the install on a clean new drive, and then slaving your existing drive to pull data off...
This is two fold... One, all hard drives fail so it's a good time to upgrade to new... Second, sometimes you risk losing your data when you reinstall or making things worse and harder to recover, both minimized by slaving the drive vs installing or tampering with it any further...
And last but not least, if it is a hardware issue I would suspect RAM as it can be very touchy and might be acting up when under the strain of launching the entire OS kernel and your start up programs...