You can improve performance on almost any computer by adding RAM, if you start with inadequate RAM for the OS you're using.

The only machine I still have running with WinXP, with maximum usable RAM still runs about a fifth as fast as even my Vista machine with it's maximum RAM. (The Vista is 32-bit so 4 GB is all it can use.)

Additionally, WinXP is unsupported and although about 50% of computers worldwide are still running it, it accounts for 80% of the serious current malware infections, that keep escaping from the infected machines to attempt to infect everyone else.

Any machine can bite you if you do something stupid, like clicking on phishing links; but any WinXP has multiple remaining vulnerabilies that can let malware in, with the ONLY requirement being that someone with malicious intent finds the machine. The holes not patched are the ones previously considered "more difficult than the easy ones" and were so rarely used that they were left hanging; but criminals now are much more willing to work a little harder (and have better tools to work with).

If you're still running WinXP I wouldn't say it's necessary to "flee in panic" if you use good AV defenses including an invulnerable firewall, but I can't recommend (or condone) buying a new machine to run it on, except perhaps as a secondary OS for dual boot if necessary for legacy programs. I would recommend using another OS (even later Windows) any time you have open web connections, if you can, and disconnecting completely from the web and any networks any time you need to turn off your firewall, regardless of what OS you surf with.

John