I am using WINDOWS XP SP2 as my OS...
i am very interested in installing various themes to my pc..
i got one windows 8 theme which i installed ...
but, after installing my system started RESTARTING continuously ..
but, i dono where the problem was i just reinstalled the OS
now .. tell me how to solve the problem..
Well you might might want to start by Downloading and installing SP3 for Windows XP = http://support.microsoft.com/kb/322389
Also make sure you have been Downloading and Installing the latest updates from the Windows Updater too as these contain very important updates especially for any security issues.
Also what type of themes are you trying to install on your machine, as many third party themes for older system tend to need a "patch" to be able to install these third party themes, not that I recommend doing so but there are plenty of them out there.
As Uvais suggested try a system restore.
Also this may also interest you here = http://www.winxsoft.com/8tp/download.html
It is the 'Windows 8 Transformation Pack 2.0'