This is more a Windows problem than a McAfee one as I doubt very much that McAfee has caused it.
For now I would cease using Quickclean and any other registry cleaner. Personally I have found that they do more harm than good.
Quickclean, set to default settings, should only do what regular computer maintenance does in any case, whether it be automatic or via the Control Panel, System & Maintenance.
Is this Microsoft document any help? http://support.microsoft.com/kb/320397
I no longer have XP but recall that NTLDR is missing was something to do with a corrupted boot sector.
If you have an XP SP3 installation disk you could try the following. (I made myself one using Autostreamer) http://www.simplyguides.net/guides/slipstream_sp2/slipstream_sp2.shtml it's for SP2 but works for SP3.
Or: http://www.winsupersite.com/showcase/xpsp3_slipstream.asp )
Go to Start/Run and type in sfc /scannow and click Enter.
Windows will then check that all system files are correctly in their original form.
You could also try this:
1. Load Windows XP CD into CD drive.
2. Make sure BIOS is set to boot to CD drive.
3. Boot the computer from CD.
4. At menu, press "R" to load Recovery Console.
5. Select the installation to be fixed.
*The following instructions assume CD-ROM is labeled as drive D and the hard drive partition the windows installation is on is labeled as drive C. Replace the letters accordingly.
6. Type "COPY D:\i386\ntldr C:\" and press ENTER.
7. Type "COPY D:\i386\ntdetect.com C:\" and press ENTER.
8. Remove CD and type "EXIT" and press ENTER (to reboot your computer).
This is 100% a McAfee QuickClean problem. I just tested it by running the QuickClean tool with a Explorer window open to C:\. I confirmed NTLDR, NTDETECT.COM and BOOT.INI were in C:\ -- I WATCHED QuickClean remove them!!!
WHY IS McAfee REMOVING VITAL SYSTEM FILES?
THIS MUST BE CORRECTED IMMEDIATELY!!!
OS: XP Pro SP 3
Could you please confirm whether are you using any other registry cleaners in the computer.Since quick clean is a pc optmisation tool it wont detect and delete any system files. Also may I know whether are you using the same computer in which the above files were deleted !