explorer.exe or taskmanager wont open

when i boot my pc it runs fine. when i log in all i get is my wallpaper nothing else i tried to open task manager to start explorer but nothing. i put disc in the drive and nothing will load. I booted up using norton it says nothing is infected but it says it only scanned 28 files. I don't have a xp disc all i have is a gateway disc that came with my laptop. my pc wont let me boot using that disc. should i get a xp disc. even in safe mode nothing happens. i don't know what to do. thank you

 

im only running sp1 i didnt download anything all of a sudden i started getting all these error messages registry ones. this morning it booted up fine so i deceied to put norton but that wouldnt let me install it so i tried mcafee and when i was checking system i dedied to restart in safe mode to delete the file and that when it happened. there is no way i can do what youj have suggest b/c i can't access anything a disc wont even auto play. so im womdering if i should go buy a new xp disc and just upgrade to sp2

 

well i asked around no luck finding a xp disc i was wondering if this website would help http://www.bootdisk.com/ and i also found this Ultimate Boot Disk/Disc/CD 4.1 Windows XP ME 98 95 2000 on ebay heres link http://cgi.ebay.com/Ultimate-Boot-Disk-Disc-CD-4-1-Windows-XP-ME-98-95-2000_W0QQitemZ290206843612QQihZ019QQcategoryZ182QQssPageNameZWDVWQQrdZ1QQcmdZViewItem not sure if that would work. or do i have to drop 150 for a brand new disc

 

i cant acess anything on my computer all i get is my wallpaper and thats it no start button i cant access task manager nothing will open at all