RMVB files keep skipping

[Skorpian]

Hello guys sup
I have a problem of RMVB Files keep skipping on my laptop which has XP SP3 2002 Pro, but my PC has win 7 ultimate plays exact same videos flawlessly
My laptop has 1 GB ram only, not enough to run win7 on it. Also, I'm pretty sure this shouldn't be happening
The codec I'm using on both is KLM Codec. Same version, exact same installation file used on both. Also, very few apps are running in taskbar on my laptop so it's not a problem with processes running.
Any ideas? Thanks
P.S : With skipping, I mean each like 3 mins, 10 secs of the video are like skipped or fast forwarded, as in 10 secs eaten outta the file. This problem is driving me crazy! Any help/suggestions are welcome

 

[MindoverMaster]

Might be apps running in the background, therefore limiting your RAM. Could be your CPU, too. Have Task Manager open to the Performance tab. See what happens when you play those videos.

 

[Skorpian]

Thanks I'll try but why especially RMVB files would have this problem and not other files such as .avi etc?

 

[Skorpian]

Okay thanks for suggestion. While video is running, CPU Usage is from 30% to 70% once lag happens it's 90% then 80% for a while. something wrong :S?

 

[MindoverMaster]

It's taking up CPU power on the rmvb, that you don't have on your notebook. Run msconfig, go to the startup tab. See what programs are working in the background on startup. If you don't know what is by the description, it's most likely you don't need it.

 

[Skorpian]

Hmm thanks for suggestion but when I go to processes tab, they don't really seem to be eating up much power. Also, why would an RMVB lag while other video types don't? Could it be codecs missing from my Laptop?
Anyway I'll try your suggestion but I don't really think there's a single process which I don't need on my startup stuff :S.