Unable to install Vista SP1.
Plain and simple if you perform a clean, parallel, installation of your operating system your problem will be resolved. It is not something everyone likes to do, but it will save you the hassle of going through the rest of this reading. WindowsReinstall.com has picture walkthroughs of performing a reinstallation, and to be honest the only hassle is backing up your data.
There are obviously a few things we'll need to know prior to being able to assist you. But, all in all I'd like to set the expectation that you may have to do a reinstallation of some type for this issue. Whether it be an "inplace upgarde", "parallel install", or "clean installation". Granted it does seem a bit drastic, but it comes directly for the Microsoft developers.
1) Do you have a technical stop code for the install failure? (ie. 0x00000000)
2) Did you receive the SP1 update via Windows Update or manual download?
The rest of the information is truly trivial because there are too many contributing factors to what may have caused the failure.
The first thing you will want to do is download and run the System Readiness Update Tool (aka. CheckSUR). This will evaluate your system's readiness for SP1, and will most likely indicate that some of your manifests, Windows Updates, are missing or corrupt. The download can be found below and if you don't know which one you need download the 32-BIT.
SYSTEM READINESS UPDATE TOOL
After you download this you will need to "RUN" it on your system. It will look like a Windows Update. When it states that it is installing you may not see a progress bar. That is normal, and please do not stop the process. If you do the results may be inaccurate.
Next, we will want to run a SFC /SCANNOW on your machine. This is called the System File Checker, and it does just that. It verifies the integrity of your system files, and attempts to repair them using backup's. If this scan returns "errors that could not be repaired" we may have a problem.
To do this please do the following.
1) Click Start > All Programs > Accessories and then Right Click on Command Prompt. After you have done that select "Run As Administrator".
2) Click "Allow" when you receive the UAC prompt.
3) You should now have a black window on your screen.
4) Please type the following and hit enter: SFC /SCANNOW
5) After the scan has completed it will give you a message indicating such.
If you receive an error message stating that "... found errors that could not be repaired" please proceed to STEP 3. If it did not find errors re-run CheckSUR, and then attempt to install SP1.
Now we will need to run CheckDisk this checks your hard drive for errors, and attempts to repair them. This scan can take anywhere from 30 minutes up to 2 hours depending on the size of your hard drive. You can execute this command from the command prompt as before or from within Windows. For ease of use I'll tell you how to do it from within Windows.
1) Click on Start > Computer.
2) Right Click on Local Disk (C:), and select Properties.
3) Click on the Tools tab.
4) Click the top most button that says "Check Now"
5) Make sure BOTH boxes are checked and click "Start"
It may require a restart before it can do the error checking, because the drive is in use. After that has completed rerun CheckSUR see if problems still persist. If not then attempt to install Vista SP1. Should you still receive errors then you will need to perform a reinstallation of your operating system.
Personally as in the "Short Version" I would recommend just doing a clean installation. It is the fastest and meets with the most success. Time and time again I've seen in-place upgrades work, but as well I've seen them cause data loss. Personally, if I'm going to do something I'd rather do it right the first time.
One of the problems most consumers are going to run into is that the computer they bought did not come with a Windows Vista Installation DVD. First off request one, because you should have gotten it. Secondly, at worst just borrow a friend or neighbors. Most times you can perform a "keyless" installation, and apply the Product Key you have "after" the installation.
If anyone has questions or concerns about the overall process please feel free to ask. Any questions I can answer here saves me from having to talk to you later down the road
If you perform a "fresh/clean" install of your OS. You can install the standalone version of SP1 on your machine without any other updates. I've done it on consumer machines as well as my test boxes. The only prerequisite updates for the SP1 package are included in the standalone. So should you have to reimage a machine or simply installing Vista for the first time consider getting the SP1 download prior to doing anything on the machine to reduce failures.