i have windows xp.

lenovo y410. 1 GB RAM!

i m using guardian antivirus.
but i dont feel its good.

can i upload anti malwares/spywares/free antivirus all together?
will it affect speed of my lapi?

I believe it should be fine. But never install 2 or more anti virus software. But I would suggest to invest in Avira internet security or any internet security software. If performance is your concern.

..installing 2 or more anti-virus software to your laptop can reduce the performance of it!..install only 1 anti-virus software..better you use AVG AntiVirus or Avira AntiVirus..i hope it helps!..^_^..

avira is free available in the net??

and will it protect from all sort of malwares, spywares too?

..yes but free anti-virus software (free avira) cannot delete/quarantine/detect strong new malwares and spywares...better you used licensed or paid version anti-virus software..^_^..

Avast is an excellent AV with a limited AS service. Comodo providess the best firewall [but one which is for people who LIKE to be prompted by a firewall doing its job].
Both are free. Combine them.