windows 7 new harddrive

so I replaced the hard drive on a laptop with one that has windows 7, I start the computer & it is stuck on the "Starting Windows" screen. I try to launch the "Repair Your Computer" program but when the advanced boot options menu shows up, the program isn't there, the solution I keep finding requires me to log into windows which is the one thing I cant do

P.S no I don't have the installation disc or the product code
P.S.S the old hard drive has no data, it was completely whipped,


Knows where his towel is.
Staff member
If you take a copy of Windows (any flavour) out of one PC and put it on another PC, unless they have identical hardware it's unlikely to get very far.
The OS gets customized during Setup with the drivers for the detected hardware.
Even if you had a W7 DVD to reinstall with, you'd need to provide a valid key for your PC.
If it originally came with anything other than W7 pre-installed, the key would be no use anyway.
If the copy of W7 came pre-installed on a different PC it will have an OEM serial number which means its EULA prohibits its use on any other hardware.
I looked at the laptop, it was originally windows vista, from what your saying I need to completely reinstall Windows 7, any way to do this without the key or cd, or do I need to get another one,


Knows where his towel is.
Staff member
If you've completely lost the old Vista, you don't even have the option of buying a cheaper "upgrade" copy of W7 (that needs an existing legitimate copy of a qualifying Windows OS to be present). I don't see any legal option short of buying a full retail copy of W7 complete with key, or a disused retail copy from someone who's switched to W8 (if you trust the seller not to be selling pirated software)