Installed Windows 7 Service Pack 1, now hard drive red light keeps blinking

[MD507]

I Installed Windows 7 Service Pack 1, now hard drive red light keeps blinking red, is that normal or is my power supply going. 

[DaveLembke]

If it is normally Green and now Blinking Red then yes your system is reporting an error. I'd check with your computer manufacturer to see what this means. And if its a system you built, look up the motherboard and the troubleshooting section to see what this error means. It could be that the system is detecting a failure in the drives near future or soemthing else.

[MD507]

the green light is on there is another light and it blinks red, the red light is the hard drive - it is blinking non-stop. There is no problem with the green light, it stays on all the time.

[patio]

I suspect more info here is needed...

[Quantos]

the green light is on there is another light and it blinks red, the red light is the hard drive - it is blinking non-stop. There is no problem with the green light, it stays on all the time.

That could just be the HDD activity light.  However, as Patio said some more information may be required.
Could you post a picture with an explanation of what you mean?

[MD507]

I don't want to sound like a smart-*** but what kind of picture was I suppose to send, I said my hard drive light was blinking red non-stop. So called Gurus' here didn't know what to do. I decided to defrag my hard drive and reboot it and Guess what Problem Solved. Wow and there are Guru's here

[Salmon Trout]

but what kind of picture was I suppose to send, I said my hard drive light was blinking red non-stop. So called Gurus' here didn't know what to do. I decided to defrag my hard drive and reboot it and Guess what Problem Solved. Wow and there are Guru's here

At least we know how to use apostrophes, question marks and capital letters properly. You posted very little information, and when you were asked for more information you just got smart and rude. Good luck next time you need any help.