I think i have a large problem but i may be overestimating (windows related)

WINDOWS VISTA 32 BIT HOME

ok so about 3 hours ago i turned on my computer as normal and windows starts up with about half of my desktop icons there, a different background and and couple of programs removed such as windows live messenger.

i press start then click on the link on the right to go to my documents. EMPTY!

so i thought i would try a different route. so went to my computer>c-drive>users

there i found my normaldocuments inside a foldercalled HOME, then underneath was a folder called TEMP which is this newly created windows with half of my desktop items.

so basically i want everything back to normal so all my programs and links are where they should be.

and i also have no idea why this happened in the first place. im not sure if this is hardware or software related.

i am using AVAST antivirus

thanks in advance

Sounds like a bad virus if you ask me. If Avast doesent find anything then scan with Spybot, Malware Bytes and then Avira Anti-Virus.