problem with free Avast download

Wow! It's really been a year since I was here? I'm a baaaddd girl! All righty then. A year ago, I had Avast! (home free edition) Antivirus installed on my computer after it got hit with a "figgler" virus.
The program has worked very well, but it's due to expire soon. I've made two attempts to re-install, but I've received an error message each time. Both errors seemed to concern server response, this computer runs Win XP and is very slow with downloads of this type.
I'm not all that tech savvy and am terrified I'll mess up. Due to my financial situation (spent a few hundred trying to save my cat's life back in January), I cannot afford another computer if this one gets discombobulated (I "inherited" this one when a family member upgraded).
I also wish to ask the other members if they can recommend another free (or a low-cost) anti-virus program which would offer similar protection to Avast! If I continue to have problems with Avast!, I will definately need a good replacement to protect this computer. Thank you one and all. Have a good week!:wave

 

Hello, uninstall avast 4.0 from control panels add/remove.
Then run this avast uninstall utility. Reboot and run again.
http://www.majorgeeks.com/Avast_Uninstall_Utility__d5528.html

Get the latest Avast 5.0v from under.
http://www.majorgeeks.com/Avast_Free_Edition_d1968.html

Cheers..

 

Another very good free AV is Avira AntiVir.