Why is C521 not compatible for Windows 7 upgrade?

Try using the Microsoft Upgrade Advisor, and see what it says.

This past weekend, I finally got around to trying to upgrade my Dimension C521 to Windows 7.  I ran the Microsoft WIN7 Advisor and it replied with no issues for the upgrade.

However, when running the upgrade function (custom install), the system hangs up terminally at 27% of programs being extracted (the second step in the process).  I've run it now 4 times, and each time it hands at the same point (27% extracted).  

Any suggestions on what I can do to reduce whatever roadblock there is, to allow the full install to happen?

Did you download the ISO or purchase an actual disk?  I would suspect the installation media at this point and would suggest downloading it again.  What OS are you running this on?

Hi,

The upgrade discs were retail purchases sometime last year.  Current OS on the Dell is XP, as supplied with the computer when I purchased it in 2006, although several service packs have been applied since then.

The MS WIN7 upgrade advisor recommended using the 32-bit version disc that came in the upgrade purchase, vs the 64-bit one.  This is what I did.

One thing I have not done is reformat the C:drive prior to attempting to install the upgrade.  Do you think that will make a difference?

TAMercer

Unless there is a particular reason why you are trying to run the install from within Windows ... I would just backup any files you want to keep (if you have not already done so - I'm assuming so, since you were already about to install), then follow this article to perform a "clean" install of Windows 7 with the upgrade media (IF you are not able to simply boot to the Windows 7 media):

www.mydigitallife.info/clean-install-windows-7-with-upgrade-media-and-product-key-on-formatted-or-empty-blank-hard-drive

Simply put, clean installs with upgrade versions where the disk is reformatted need to be done twice. The first install partitions and formats the hard drive, and the second install is done without reformatting, after which the first install is "archived" in its own folder (I believe it's called Windows.old) and you can delete it.

If an upgrade is used for a clean install and it's not double-installed as just detailed, the product key won't activate.

There is a way around the double install to get a Clean Install see Workaround 1 here:

http://www.mydigitallife.info/clean-install-windows-7-with-upgrade-media-and-product-key-on-formatted-or-empty-blank-hard-drive/ 

I have verified it to work on a system; I had to clean install and wipe an Inspiron 6400 with DBAN recently which was severely infected with Malware. It was eligible for the upgrade as the OS was being reinstalled but wiping it with DBAN made Windows 7 think that it was a new computer. The machine however contained the Vista license and was eligible for upgrade so there was no violation of the license terms it just saved a lot of time than reinstalling twice. I will probably incorporate the fix in my next revision of Reinstallation guide.