Upgrading to 32bit Win7- could not boot to next phase

So i'm trying to upgrade from vista 32 bit to 7 32bit using an official CD. Doing a clean install isnt something I can do b/c I dont want to lose everything on my harddrive. When I do the upgrade I get the error "Windows could not prepare the computer to boot into the next phase of installation." I've tried disabling everything but microsoft services at bootup before installing, but to no avail. The compatibility checker thing doesn't come up with any problems before installation. I've got over 20gigs of space still on my harddrive, so I don't think that's the problem. I've also run the chkdsk utility from the command prompt, but I don't think it found anything.

Any ideas to help?

Take it from someone who has upgrade and installed many windows machines. I know that you don't want to loose your stuff but I would really really recommend that you do a clean install. If all possible, borrow a hard drive from a friend or if your living in the states with our great customer service at Best Buy, Walmart.. you can use the drive for the time being and return it.

I know this is not the answer you are looking for but it will prevent a lot of problems in the future. I have heard of a lot of lower bench markings from people upgrading instead of clean from vista to windows 7

that isn't a practical option for me. Trying to reinstall everything I have would take days to do. Besides, in searching for solutions to this problem, it seems that people have had a similar problem even with a clean install.

You need to backup your files anyway when doing an in-place Upgrade so why not clean reinstall to avoid the problems you're already encountering?

Clean Install with a Upgrade Windows 7 Version

If you can't afford an external to back up properly, you can send files over network to another computer or use DVD's. Or a last resort would be to create a data partition on the right end of your HD to move files, then clean install to the front partition.

Its not an issue of affordability of a hard drive. Rather, it is the hassle involved that would be required for me to reinstall all of the programs I need. So much in fact that I'd choose to retain vista over having to reinstall everything with 7. Additionally, in looking around for answers, people seemed to have had this problem even when doing a clean install. I know it may be easier to suggest to just wipe everything, but I am looking for a solution. Since this seems to be a fairly wide-spread problem, do you all have any idea of the cause of the problem, whether its the SCSI controller or a corrupted BIOS or something wrong with the partitioning of the hard drive ?

Did it already. It said I had some problem with SCSI/RAID controllers. Turns out a virtual CD program (Daemon tools) was the thing that was causing it. Once I uninstalled it, the compatibility issues went away

If you have RAID, be aware that we see tons of problems here with Win7 install to RAID. Even though it should be able to use Vista RAID drivers, Win7 still doesn't much like RAID.

Disable your AV protection.

Make sure your Updates are current.

Disconnect all other HD's and peripherals.

Type msconfig in Start Box, on General tab click Selective Startup, clear Load Startup Items checkbox.

next on Services tab, check box to Hide All MS Services, then check box to Disable All.

At prompt, restart computer. Then run Upgrade again.

Hope it helps. If not, there are more.

I have SCSI and the compatibility checker doesn't appear to have a problem with it. Also, as I mentioned in the original post, I've tried disabling everything except the microsoft services at bootup before installing, but it didnt work.