Slow during and after startup - svchost.exe?

Hi all, I recently bought a refurbished laptop and I've been having a lot of problems to deal with. After I've (apparantly) managed to qualm most of them, this one has risen from being common to frequent, to the point where it's seriously making me question my hardware.

For a quick run down of specs, I'm running Home premium 64-bit on an Advent Roma 4001, Intel Dual Core T4400, 4GB RAM and 500GB HD.

It's during the log-in screen that it tends to hang, on both the "Please wait..." and "Welcome" messages it takes between 30 seconds - 2 minutes, but the main problem occurs after logging in. The CPU usage, apart from System Idle Process (of course) is pretty much zero, and the RAM usage is down at about 30MB. Everything seems responsive, however, when I attempt to open a program or process I'm getting incredible lag, the type of unresponsiveness that would tempt you to do a hard reset.

The strange thing is it doesn't actually appear to be unresponsive. The programs all load given time and, for all running slowly for an amount of time, still run. What I have noticed is that svchost.exe seems to kick in at an undefined time and puts the RAM usage up to about 62,000K, with the CPU usage still being very low. When terminating the process, the theme will lose it's transparenecy and revert to a white theme, with processes continuing to run extremely slowly, until a few minutes pass, the windows 7 theme (with transparency) kicks in again and everything loads up immediately. After that, everything's fine - lightning fast.

I've tried chkdsk, messing around with msconfig and various other things to no avail. Am I missing something here? I'm stumped. I think given the problems I've been having aside from this (booting) I'm tempted to put it down to a faulty CPU or Harddrive (the 500GB size supports that probability, I think).

Does anyone have any suggestions?

Thanks, Anton.

richc46 said:

Anton,
Try a clean boot
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7

If it makes you work properly, follow the instructions

If it does not work, try in safe mode and report the results back to us.

A clean boot did not solve the problem, everything happens just the same. (Although, it did seem to clear itself after about 5 minutes without terminating svchost.exe).

Everything ran fine in Safe Mode (with networking). No lag at all. It may be worth noting that in Safe Mode svchost.exe was clocking @ 6,000k instead of 60,000.

richc46 said:

With those facts, good chance that it is a driver.
Go to device manager and look for any yellow warning markers.
Make sure that the graphics driver is up to date.
Do the same for audio.

No yellow warning markers, and Windows determined that the sound and display drivers are both up to date.

richc46 said:

Check out your event viewer, from search. Any critical errors? If we can find which driver problem should be solved.

No critical errors but a shed load of errors, 99 in the last hour. 78 of those were Disk (event ID 7). In the last 7 days I've had 1,126 errors and 893 of them have been caused by Disk.

richc46 said:

Scchost should not spike like that, something strange here.
Run your anti virus
Download and run a full malwarbytes scan. update it first.

Thanks for your quick suggestions, I'll give them both a run and let you know.

A full anti-virus scan brought up no infections, the same with Malwarebytes. I've been trying the suggested help prior to starting this thread, hence being stumped!

Malwarebytes' Anti-Malware 1.46
Malwarebytes

Database version: 4968

Windows 6.1.7600
Internet Explorer 8.0.7600.16385

28/10/2010 01:01:27
mbam-log-2010-10-28 (01-01-27).txt

Scan type: Full scan (C:\|)
Objects scanned: 235237
Time elapsed: 36 minute(s), 57 second(s)

Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 0
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 0

Memory Processes Infected:
(No malicious items detected)

Memory Modules Infected:
(No malicious items detected)

Registry Keys Infected:
(No malicious items detected)

Registry Values Infected:
(No malicious items detected)

Registry Data Items Infected:
(No malicious items detected)

Folders Infected:
(No malicious items detected)

Files Infected:
(No malicious items detected)