It is hardly worth buying a new XP license - the computer has no value.
Reload the op system that it came with if your op system is corrupted and malfunctioning.
If you do not have a software firewall get one of the free ones:Software firewalls with freeware versions
Free Zone Alarm SE: http://www.lavasoftusa.com/support/download/http://www.zonelabs.com/store/content/comp...;NONE?lid=ho_za
Sygate: http://www.sygate.com/Antivirus programs - freeware
(you can only use one resident anti-virus program on your computer. More than one will conflict)
Avast Anti-virus freewarehttp://www.komando.com/bestshareware.aspAnti-malware freeware
(You can run as many of these as you wish. Generally there is no conflict between these and you should always run several)
*AdAware SE: http://www.lavasoftusa.com/software/adaware/
and the add-ons for Adaware: (What are add-ons for Ad-Aware, what do they do, and how do you use them?
Add-ons are designed to enhance and extend the protection that Ad-Aware provides for your system. They aren't strictly necessary to effectively using Ad-Aware, but they can add an extra layer of defense against privacy and security intrusions. They can stop potentially dangerous Windows services or provide additional information about suspicious files or activities that may be helpful for the user, IT professionals, and Lavasoft.
Add-ons for Ad-Aware are also available and come in two varieties: tools (they can be used without performing a scan), and extensions (used once a scan has been finished, although generally not for use with Registry entries).
Current add-ons available at no charge from Lavasoft are:
Installing a add-on is simple, after you've downloaded a add-on and closed Ad-Aware, extract the installation executable from the archive and run the downloaded file. The installer will handle finding your Ad-Aware add-in folder and automatically install it for you. The next time you run Ad-Aware, click on the "Add-ons" option to use your installed add-ons.
*Spybot S&D: http://www.safer-networking.org/en/index.html
Microsoft Antispyware Beta: (Win 2000 and XP only) http://www.microsoft.com/athome/security/s...re/default.mspx
Microsoft Malicious Software Removal Tool (Win XP and Win 2000):http://www.microsoft.com/security/malwareremove/default.mspx
AČ - Free from http://www.majorgeeks.com/download4281.html
. Run it, click Search for Updates, then click Scan.
Also, run some of the following web based scans:Web based online Antivirus and anti-malware scans:
(these can be run regardless of whatever else you are using. You must use Internet Explorer to run these.)
Kaspersky Anti-Virus Web Scannerhttp://www.kaspersky.com/service?chapter=161739400#betatest
Panda Activescan http://www.pandasoftware.com/activescan/co...n_principal.htm
Trend Micro antivirus and malware scan:http://housecall-beta.trendmicro.com/en/st...orp.asp?id=scan
Etrust Anti-virus web scannerhttp://www3.ca.com/securityadvisor/virusinfo/scan.aspx
online trojan scans here - http://scan.sygatetech.com/pretrojanscan.html http://windowsecurity.com/trojanscan
Windows Security Trojanscanhttp://www.windowsecurity.com/trojanscan/trojanscan.asp
Don't spend a lot of money on that old computer.
You can buy a new computer with current technology and with XP on it for $300.