CPU Usage Very High!

hello,

I have a question concenrning my cpu usage, my computer has ben running very slowly laterly so i downloaded a piece of software which cleaned my computers temp files up and permissions etc. Which helped it but now is running bad again so i go onto terminal and type in top, to get all the running apps up right? anyways i see the colum %CPU and find that finder is at about 50% is this right? i also am concerned about this:

Processes: 65 total, 3 running, 1 stuck, 61 sleeping... 215 threads 17:55:22
Load Avg: 2.36, 1.95, 1.84 CPU usage: 16.5% user, 81.0% sys, 2.5% idle
SharedLibs: num = 218, resident = 41.1M code, 4.16M data, 8.27M LinkEdit
MemRegions: num = 7010, resident = 101M + 6.61M private, 87.9M shared
PhysMem: 96.1M wired, 216M active, 249M inactive, 562M used, 77.5M free
VM: 4.55G + 132M 52147(0) pageins, 7453(0) pageouts

Is that ok, or would that take a affect to my computers performance?

Thankyou in advance

Martin