you have a few optins.
you can live in the res hall. ONLY rieber hall will be open for summer school students. they provide meals and internet access and other goodies. as for the antivirus, i don't know, that's new this year and i don't live in the dorms this year. BUT if they know it is YOUR port that is propagating a ton of viri or have abnormally high traffic, they WILL shut it off. i wouldn't be surprised if they did make you install an antivirus program because there were so many problems with viri last year. living in the dorms is quite pricey and you'll be with a lot of international students also.
you can also sublet an apartment nearby. tons of people will be advertising sublets soon. check
the community housing website for info. you won't have internet access unless its already hooked up.
i don't know if campus run apartments are rented out for the summer. try
ucla summer sessions website for info on housing (should be a link somewhere) my lease is up in july so i won't be subletting my apartment but there are TONS of people that will be.
if you want to park - you CAN buy parking for the summer, but make up your mind ASAP. they sell it first come, first served for the summer.
parking services at ucla street parking sucks as there are two hour limits everywhere and on the rich side of campus the old people there bitch like mad if you park.
start looking as soon as you can, sign up for classes as soon as you can, as even though the schedule of classes may say "unlimited" some classes will be closed.