http://www.techrepublic.com/article/10-things-you-can-do-when-windows-xp-wont-boot/6031733

January 26, 2006, 8:00am PST Note: This article is also available as a download.

When your computer hardware appears to power upokay, but the Windows XP operating system won't boot properly,

http://www.rickrogers.org/fixes.htm#Installation

msiexec

Try cleaning up the installer. Click start/run, type services.msc and click “ok”. Scroll down to “Windows Installer” and double click it. Stop the service if it is running, set the startup type line to disabled. Click apply/ok and reboot.

Delete the contents of the temp folders, there may be a file in there interfering with the setup routine of the installer. Check both:

C:\Windows\temp C:\Documents and Settings\<username>\local settings\temp

http://www.bleepingcomputer.com/tutorials/how-to-see-hidden-files-in-windows/

keyword: virus hidden

http://techlogon.com/2011/06/07/folders-and-documents-hidden-by-virus/

http://download.bleepingcomputer.com/grinler/unhide.exe

http://support.microsoft.com/kb/314056

Tasklist /SVC

Svchost.exe is a process on your computer that hosts, or contains, other individual services that Windows uses to perform various functions.

http://www.howtogeek.com/howto/windows-vista/what-is-svchostexe-and-why-is-it-running/

Some time ago, Microsoft started moving all of the functionality from internal Windows services into .dll files instead of .exe files. From a programming perspective this makes more sense for reusability… but the problem is that you can’t launch a .dll file directly from Windows, it has to be loaded up from a running executable (.exe). Thus the svchost.exe process was born.

http://svchostviewer.codeplex.com/

A program to see what all those svchost.exe are running.