You can read about Error performing inpage operation here:
http://support.microsoft.com/default.aspx?scid=kb;en-us;141117It sounds like your hard drive may be failing
Error performing inpage operation is a sign of bad sectors, clusters, sometimes
chkdsk /r can fix this error.
i would suggest backing up all data as soon as poss incase your hard drive is bad.
Here is some more info
Cannot copy: Error Performing Inpage Operation
Symptom:1. When copying files from a diskette or CD on a Windows computer, you may occasionally experience an "Cannot copy: Error performing inpage operation".
2. When trying to open a file from Removtable hard drive or CD, you may receive this message: "Error performing Inpage operation"
3. In some cases, you may be able to copy small file but not large file.
4. In other cases, you may not be able to copy using Windows Explorer while using xcopy works fine.
Causes:1. This error usually indicates physical problems on the media.
2. Additionally, errors caused by network connectivity can cause these errors.
3. Mismatched MTU sizes or truncation of a packet at a router can result in this error when files larger than the largest packet size are copied over the network.
Hope this helps you out.