I tried installing ubuntu server alongside my windows 7 from a usb drive. After the partitioner level, the installation gives this: warning: file:///cmrom/pool/main/c/coreutils/coreutils_8.5-1ubuntu6_amd64.deb was corrupted. Should I download another server file? Or is there another way to solve this problem? Thanks in advance
First, I would check the MD5SUM of the .iso you downloaded, to make sure that isn't corrupted. Here is a link to a tool to check the MD5SUM on Windows: http://www.georgejopling.co.uk/md5check/md5check.html and here is a link to the MD5SUMs of the current .iso's to compare against: http://releases.ubuntu.com/12.04/MD5SUMS. If the MD5SUMs don't match, redownload your iso, because that is the problem.
If everything looks gravy, I'd just try and recreate the flash drive installer.
Since the warning says that the coreutils package was corrupted, you should probably download a new iso image of Ubuntu. But one thing that you should try before downloading a new iso image, is to check the checksum of the file you have with ou now, to ensure that it is not corrupted-
Assuming that you are using ubuntu-12.04-server-amd64.iso