Windows 7: there's a lot of failed update on windows update history?

i just reinstall my windows 7 home premium last night, and after i click the update button i left it alone and couple of hours later i saw a lot of failed update on windows update history?

these unfinished update will it became a trash on my computer or just simply gone?

how to delete these failed updates?

thx,

You don't delete failed updates - it just means that they didn't install at that attempt (possibly your connection got broken)
Go back to Windows Update again, check for updates again, and install ONLY the Security updates for Windows itself (not .NET, or IE etc.) , then go back and do the rest of the updates for Windows, - then do IE, and lastly do the .NET updates.