Is Windows XP SP3 without any more updates secure

I plan to put third party Anti-virus, firewall and anti-spyware on it to try to plug up what holes I can. This is just for a virtualmachine so I'm hoping it will be secure enough.

the only problems MS has been solving about XP SP3 are related to their RDC client, which is now know to have some vulnerabilities.
and the only reason they are solving it is due to possible exploits when communicating with either vista, win7 or server 2008, which use a more secure client than XP.
It's basically maintenance the other updates, the only security ones are those i explained.

So i'd advise to turn off remote access to that machine, and you'll probably be fine. (In case you're going to let that VM access the virtual LAN created in VMWare.)
Just don't run any critical services on it, XP is a major piece of shit.

well MS has already stated they won't be serving XP any more upgrades so even if it is ok to use XP atm (which it is - I'm using it too)...I'm afraid that probably won't remain the case after maybe an year or 2 at best

Heck you can can run XP SP2 as long as you don't connect to the net much. Like for a gaming machine you use for single player (no online gaming) games. You would just connect briefly when you need to activate a game and then disconnect again. Not every computer you own has to be connected to the net at all times. I found that with each SP MS released for XP, the system became more and more faulty. Even though SP3 was supposed to speed XP up, it also added some glitches as if MS was trying to break it so you had to buy Vista. One such glich is System Restore. In SP1 it works flawlessly, in SP2 it sometimes fails and in SP3 you nearly always have to do it from within safemode or it fails. Whats up with that?

Vulnerabilities come into play when your surfing around unfamiliar territory and you get hit by a drive-by download of some malware or virus, or you reclessly open e-mails without protection or care. there are alot of people out there who claim they never use anti-virus and have never been infected. If they visit the same sites and don't ever download anything or open e-mails it certainly could be true. A firewall is absolutely necessary though if your going to connect for even a few seconds. When I had Zone Alarm set to warn me at every attempt to connect to the PC thru the firewall, I got so many warnings I had to change the settings for sanity reasons, nasty hackers are relentless.

well if u don't go online, then you can probably use something like win 98 and still be fine

The XP SP3 Virtual Machine will be going online.

As long as you keep your software firewall rules strict, you will be ok. I mean, you also do have protection at the hardware level in your wireless router.

If the VM has a direct connection to the internet, it is prone to massive port scans and you need to set up your XP to refuse these unsolicited scans/requests.

Hmm it'll be better to move to win7. XP will not be supported soon I guess

Updates are security patches, so no.
But if you are running windows anything should be a risk.

If you go to 7 and run your firewall thight you should be safe, but never pay for it.

I run linux, what do I know anymore.

If you think xp aresn't secure anymore you can use linux or windows 7 or mac os

To keep your surfing safe, install opendns, that will stop you from going to known malware phishing sites.

Is Windows XP SP3 without any more updates secure? Absolutely not.
Only during this month, 10 security updates has been released, at least.