Overwrote registry file. Software not working

Hello,

My old hard drive crashed. I bought a new drive and reinstalled the OS and other software. But Windows product activation was not working after I reinstalled Win XP Pro. Running msoobe.exe did not work either. (It did not do anything, after I click Run, no new window opens up). So I did this. I copied these files/folder form my old hard drive (I am still able to access all the data from my old drive) and pasted to my new drive.

1. /system32/oobe/
2. /system32/config/software

After I did that, I was able to run windows product activation.

But now I am not able to run any of the installed software (I am 'guessing' because I overwrote software registry file). Is there anyway to fix the issue? I did backup 'software' file before I overwrote it. Is there anyway to read values from this file? I would really like to get at least these two working - Visual Studio 2008 and MSSQL 2008. It would take me a long time reinstalling and setting up the old projects and databases.

Thanks.