Here's a text file from Process Explorer when the slow down occurs:
Process PID CPU Private Bytes Working Set Description Company Name
vlc.exe 2840 35.22 124,192 K 102,460 K VLC media player the VideoLAN Team
svchost.exe 2976 79,260 K 14,192 K Host Process for Windows Services Microsoft Corporation
svchost.exe 864 < 0.01 50,704 K 58,336 K Host Process for Windows Services Microsoft Corporation
explorer.exe 2012 0.23 47,292 K 51,904 K Windows Explorer Microsoft Corporation
dwm.exe 1768 15.36 40,832 K 20,900 K Desktop Window Manager Microsoft Corporation
svchost.exe 788 20,360 K 20,472 K Host Process for Windows Services Microsoft Corporation
SearchIndexer.exe 2316 19,636 K 14,620 K Microsoft Windows Search Indexer Microsoft Corporation
procexp.exe 1776 30.71 15,908 K 26,068 K Sysinternals Process Explorer Sysinternals -
www.sysinternals.com
audiodg.exe 4048 5.88 15,800 K 14,364 K
svchost.exe 896 0.68 14,472 K 26,728 K Host Process for Windows Services Microsoft Corporation
svchost.exe 1308 0.12 14,092 K 16,708 K Host Process for Windows Services Microsoft Corporation
svchost.exe 1484 10,624 K 11,444 K Host Process for Windows Services Microsoft Corporation
svchost.exe 2832 0.02 8,720 K 10,368 K Host Process for Windows Services Microsoft Corporation
wmpnetwk.exe 2428 0.03 8,616 K 8,008 K Windows Media Player Network Sharing Service Microsoft Corporation
taskhost.exe 1336 7,004 K 6,892 K Host Process for Windows Tasks Microsoft Corporation
svchost.exe 1452 0.13 6,828 K 14,124 K Host Process for Windows Services Microsoft Corporation
svchost.exe 1064 0.02 6,532 K 11,508 K Host Process for Windows Services Microsoft Corporation
services.exe 488 4,768 K 7,096 K
spoolsv.exe 1416 4,548 K 8,456 K Spooler SubSystem App Microsoft Corporation
lsass.exe 532 3,196 K 8,304 K Local Security Authority Process Microsoft Corporation
svchost.exe 736 2,940 K 5,824 K Host Process for Windows Services Microsoft Corporation
svchost.exe 664 2,856 K 6,676 K Host Process for Windows Services Microsoft Corporation
rpcld.exe 1496 2,664 K 6,280 K
AppleMobileDeviceService.exe 360 0.05 2,464 K 7,932 K MobileDeviceService Apple Inc.
csrss.exe 440 1.77 1,840 K 13,464 K
iPodService.exe 2132 0.10 1,760 K 4,904 K iPodService Module (32-bit) Apple Inc.
winlogon.exe 520 1,688 K 4,576 K
rpcnet.exe 1648 1,592 K 4,740 K rpcnet Absolute Software Corp.
mDNSResponder.exe 3228 1,488 K 4,200 K Bonjour Service Apple Inc.
csrss.exe 380 0.01 1,324 K 3,152 K
lsm.exe 540 1,236 K 2,880 K
WUDFHost.exe 1168 1,044 K 3,800 K
wininit.exe 432 1,040 K 3,400 K
smss.exe 300 264 K 756 K
System 4 1.13 52 K 2,312 K
System Idle Process 0 0 K 24 K
Interrupts n/a 2.96 0 K 0 K Hardware Interrupts and DPCs