If you mean can you use a retail Windows 95 CD as qualifying media for an
upgrade and do a clean install, the answer is yes. If you mean can you
upgrade over a Windows 95 install, the answer is no.
Now, if your machine was made for Windows 95 or in that period, before you
consider moving to XP you should run the compatibility Wizard. However, if
you run it with 95 installed on the machine, it may just tell you this is
not an approved upgrade path and stop. If you have something later on the
machine, even Windows 98, you can at least run the wizard and get an idea of
what needs to be updated before you install XP.
You can download the wizard from the following site:
http://www.microsoft.com/windowsxp/pro/howtobuy/upgrading/advisor.asp
If this system was running Windows 95, I strongly recommend you buy another
computer with XP as opposed to this venture. If you are determined, you'll
need to update all your drivers, if no XP drivers exist for a specified
device you'll need to get new devices, it's likely most or all of your
applications will need to be updated to the latest versions. All disk
tools, antivirus, CD burning and firewall software will need to be replaced
as pre-XP versions are not compatible.