USB devices cause horrible spike lag when used with MapleStory.

For the longest time, I've had severely aggravating issues with significant frame rate drops every few seconds when playing MapleStory. Lately, I've switched to another computer, but that lag also occurs with that computer... It couldn't be coincidence... >_>

So... With my laptop free of USB devices, I've been playing MapleStory on it simply because I've been too lazy to start up the desktop computer lately. That's when I noticed... I have absolutely no frame rate drop issues (aside from the normal "MapleStory can't run very well on this computer because it now requires 10 gigabytes of RAM and a 4 Gigahertz processor, and a top-of-the-line graphics card to run" lag). Intrigued, I plugged my USB mouse (which is brand new) into my laptop and I start getting that horrible frame rate drop issue every two to five seconds when playing. I unplug it and try the USB keyboard (which is old as dirt) and the same thing happens. I can easily side with playing MapleStory on my laptop, but there are issues... My keyboard is only half-functioning because it's old, worn out and busted up. I can't run anything while MapleStory is running, so I have to use another computer for things like Skype, Windows Media Player, and so on. That means I have to use my laptop for Skype, music, and so on while I use the desktop for MapleStory if I want to talk to people or listen to music when playing. This means I'll have to use the USB keyboard and mouse on the desktop, making the game have very significant frame rate drops (even worse than my laptop, somehow).

Is there any way I could possibly fix this? I can't seem to figure out what the hell the issue is. I've tried updating the drivers for my USB devices... They're all apparently up to date. I don't really have any option but to use these USB devices, unless I don't want to use the desktop at all and want to burn my lap with my laptop.