An ffmpeg front end combined with a VB download app.
Search your system drive, particularly the C:\Windows folder for MSCOMCTL.OCX & msinet.ocx . If you find them in the Windows folder [likely in the System32 or SysWOW64 subfolders], register the file(s) at that location with Windows [I use Regdrop but Google as there are plenty of tools as well as instructions on using Windows included regsvr32.exe]. If one or more of these files is included in another program folder [excluding YouTube To MP3 HQ Downloader], copy the newest to one of those Windows system folders & register there.
Files are installed to YouTube To MP3 HQ Downloader & C:\Documents and Settings\[UserName]\Application Data\ & the Start Menu.
Lots of registry keys but all for the two files listed above with one exception: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\YouTube to MP3 High Quality Downloader_is1]
You can try to get rid of the other keys/entries by un-registering the 2 listed files -- Google for instructions using regsvr32.exe -- but only if the only place you find them is in the YouTube To MP3 HQ Downloader folder.