For a budget like that, best to buy a monitor /computer combo.i would be looking at brand like HP, Acer, and even a gateway probaly. Probally a really fly eMachines.
I would say u would need atleast 512 ram for just web browing, but then i notice u specified vista. for that u would need at least:
2gb RAM
120gb HDD (this is up to u because hdd can be added really easily)
let me see some suggestions from BEST BUY:
http://www.bestbuy.com/site/olspage.jsp?skuId=999988700050013&type=product&id=pcmprd88800050013
this should be good. Great processor, i own its big bro.DEFINETLY enough hdd space so your all good there. and RAm is good too. if u want more (prob another gig, it would cost probaly like $25 a stick off sale.)
at frys electronics:
this is really good but without a monitor:
http://shop2.outpost.com/product/54...Ydhrve4tg**.node3?site=sr:SEARCH:MAIN_RSLT_PG
neighborhood Walmart?
http://www.walmart.com/catalog/product.do?product_id=8221531
great company, but not as flashy as the Best buy comp, and needs another gig of ram.
there ya go. If have any questions just post back here