I am noticing that some machines in our environment are taking 3-4x the time to install an application from Software Center on pre existing machines and newly imaged machines. There is nothing running in the background and it continues to be slow even after a reboot. For example Office 365 package generally takes 15 minutes to download and install but the other day I noticed a freshly imaged machine taking just under an hour to install that same exact package. Again, no other installs or any applications running in the background.
I've thought of restarting the BITS service next time we encounter this to see if that helps but I don't know if that will. Is there anything else that can be done in these scenarios?
We need more info:
Is it all applications?
Is it all hardware?
Is there any difference between machines that have a problem?
Are the problems all on remote machines (VPN), WAN or anywhere?
Does the software download to the cache OK or is it the actual install that's slow?
If a machine shows the problem is it all software installs are slow or does it vary (some do some don't)?
If you can't answer the above I suggest doing test deployments of something easy. Create a deployment for 7zip and target some machines that have issues and some that don't. Track the behaviour with logs.