Windows 7: Urgent help plz

Hey guys...plz help me out as soon as possible...i thought of changing the windows startup sound using the tutorial on this site...i renamed imageres.dll to imageresold.dll....it automatically made a file called imageresoriginal.dll also...within the system32 folder...i was continuing with the prOcess when my house lights went off nd obviously my pc also went off...then wen it came back i turned on my pc nd nw its stuck on the startup screen when the windows sound plays....i cnt do anythn...even its stuck on d same thing in safe mode also...nd for the worse i dnt hve my windows7 ultimate bootable dvd with me nw...plz help me...i tried to insert windows xp bootable also but it isnt booting...plz help me guys...im on windows7 ultimate build 7600

Try Last known good configuration?: Advanced Boot Options

If your last good doesn't work, then maybe try getting to the c prompt and copy the file back over from the imageresold.dll

Command Prompt at Startup

Hi akshaykapoor and welcome to Windows 7 Forums

Try System Restore You will need to use Method Two.

If that doesn't work, then try Advanced Boot Options Select Last Known Good Configuration

Failing that, you might need to Repair Install

Dwarf, I think he doesn't have the install disc (thus no system restore). and cant get into safe mode or windows (thus no repair install).

Is there another startup repair maybe? that too requires install disc though.

maybe you can get into safe mode after a few tries?

Try the Last good configuration. Last resort if you cant do any other repairs or get into Safe Mode or past boot screen, then try to get to the C Prompt.

If you get to the c prompt,

using rename [drive:][path] filename1 filename2
Rename - Rename Command Details - Recovery Console Command - Ren

your changes should be:

(rename the current one so we dont do worse)
rename C:\windows\system32\imageres.dll imageresbad.dll

(rename the backup to the good name)
rename C:\windows\system32\imageresold.dll imageres.dll

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Edit: look at tutorial again I think you have to do step

4. Repeat steps 17 to 24 above to restore this file.
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and then type EXIT

If Last Known Good Config doesn't work after tapping F8 at bootup, burn a Windows 7 Repair CD, boot and accept any offered repairs after it discovers installation.

If no offered repairs or fail, then boot back into Recovery Tools list to run Startup Repair repeatedly until it starts.

System Restore is automated in Startup Repair but if necessary, choose it from the list and work back through Restore Points until it starts.

System Repair Disc - Create
Repair CD - System Repair Disk