Re installing XP:
a. If you have a genuine XP install disk (not recovery disks), then any install of XP is easily accomplished. Since this is a laptop, it's unlikely that you have anything other than the Lenovo disks which would have enabled you to restore the system to factory defaults. These disks may be of no value if the hard drive issued with the system has been replaced or been wiped by a more recent install of an O/S.
b. Since I continue to use my XP install on one of my systems, I won't rail against such . But I will remind you of the significant risks that go with using an O/S that is unsupported and highly vulnerable to malware in 2016. IE 8 is not acceptable at many websites because of the known security vulnerabilities which IE 8 does not address (no critical updates since more than 2 years ago), while the amount/types of malware continues to increase (seemingly exponentially). AV support for XP has been pulled by some of the major players/developers. Even with AV support, the lack of critical updates for the O/S itself...justifies nof even considering installing such in 2016.
c. Windows Update/Microsoft Update appears to still provide the old critical updates available thru 2014 for XP...for users who have not previously installed such on new/current installs of XP.
d. I just looked at my 2016 update history for XP. There are 2 types:
a. Those for MS.NET. I believe that these originate from the Microsoft Update site and will not apply to users who either do not have NET installed or have not automaticlaly been shuttled to Microsoft Update because they have other Microsoft apps on the system.
b. Those for the Malicious Software Removal Tool (Windows Update is the origin).
e. If the media used for the XP install does not reflect SP3, you will have a large number of critical updates that will need to be installed. Even if it reflects SP3, there are at least 200 (by my last count) of critical updates that would need to be installed to take any user to the Apr 2014 end of life for XP. After that, there were maybe 5-10 critical updates released for XP which are not the Malicious Software Tool.
Bottom line: I would not recommend anyone seriously consider installing XP as a primary O/S in 2016. History does not support such an idea/decision.