Hi
My PC is:
Windows Vista Home Premium 32-bit SP2
Intel Core 2 Duo CPU E4500@ 2.2GHz, 2.0 GB RAM
NVIDEA GeForce GT 730.
Not a particularly hi spec machine but it runs VP reasonably OK. even with quite large projects. You should not be getting such slow performance with a sequence only 15 seconds in duration. Reinstalling VP (latest version) may be a way of resolving this as will clearing the cache file. Also do you have many background jobs running and have you checked for malware?
Open up the task monitor and check the performance. At rest the utility process monitor really shouldn't run at more than 50% but it can jump up to 90 odd % when the PC is working hard as it does during video editing. If yours is registering 100% all the time when VP is simply running or doing a smallish task like adding a transition or an effect then you would seem have other background jobs going that are slowing things down.
An application like Process Explorer (www.sysinternals.com) might also give you a clue regarding this.
Nat