|You could continue to use it as an XP system; using another browser (Firefox perhaps) as IE is no longer viable for XP. M$ are still updating its security essential as I understand. And you could install a freebie anti-virus too - there are several around that would apply OK?|
Derek has a useful item or three about continuing to run XP in a secure way. Possibly he will drop across here and advise further?
And then you could install a Linux variant; Ubuntu being a flavour much liked (and Dell even offer it for their current systems); Debian is another.
If going the Ubuntu etc option - wise to verify there are appropriate drivers for your system; and also that if you were to print from it - that your printer would be happy with a Linux variant?
Always useful to have another computer around in case of problems with your other/main; as then you can get online to seek help, drivers etc...