Hello, I have an Acer S3-391 that was bought new. Ever since having the ultrabook it has always suffered major major performance issues. I cannot watch 1080p youtube videos without it skipping and stuttering, it worsens if I leave a video to play and browse other tabs. Sometimes the system will slow down a lot doing any kind of moderately intense tasks. If Photoshop is open there may be times when a fall in performance is felt. I never had this kind of issue even on my old Turion x2 with far less ram and troublesome Windows Vista. S3-391 specs: 13.3" Ultrabook form factor i3-2377m 4gb ddr3 factory installed SSHD 20gb solid state with 300gb hdd. Swapped for Intel Pro series 256gb SSD. After upgrading to the SSD i changed to a custom version of windows 7 which I have ran very successfully for over 5 years on many systems ranging from the old Pentium D 820 to an i7-3770 and where the regular unoptimzied windows 7 would lag or begin to show performance drop outs, this custom version never did. I am very surprised that I have an issue like this as I always believed the 2377m was faster than the first generation mobile i5 cpus which were quite decent and faster than the old p8700. Does anybody have any clue what is going on? It isn't a virus problem because it has shown the same symptoms with a fresh windows 7 after doing the SSD. The lag and stutter was far worse prior to upgrading to the SSD. I used to have a Vaio FW140E with a p8700 Core 2 Duo cpu before this and never once had a problem doing the same things. The Vaio also felt much faster than the s3-391. I'm about frustrated with this problem because I really use the ultrabook for a lot of media consumption as well the occasional creation or two.